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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Original Post - Oct 23, 2010 - 08:42pm PT
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Picked up some Redhead 1/4" Nail Drive anchors. I didn't realized the body was zinc or I wouldn't have bothered but I had them so I tested one anyway. The zinc sleeve popped in tension (prying) at 620 lbs (2.7 kN). When the sleeve broke, it pulled the nail and loosened the anchor so it fell out without damaging the hole.
I then used the same hole to test a 1/4" stainless wedge anchor that Cragnshag gave me. Seems to be a Hilti. The bolt popped in combined shear and tension at 2450 lbs (10.9 kN).
The hole was hand drilled. Something to do on a rainy Saturday at home.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 23, 2010 - 08:57pm PT
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One more reason the zmac rivet is more than ample for a ladder.
What about sheer strength on the nail in?
Thanks for the test.
Mucci
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tomtom
Social climber
Seattle, Wa
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Oct 23, 2010 - 09:06pm PT
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Just a demonstration of Archimedes Principle. Given a long enough lever, you can pull just about anything out.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Oct 23, 2010 - 09:42pm PT
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Actually, I hypothesize that 1/4" steel, split shank, button heads are significantly stronger than the zinc nail nail drive - send me some and we'll see. Look at matweb.com for zinc. The stuff is like butter. They say plain zinc has an ultimate strength of 5370 psi. (Of course I don't know what alloy they might use in anchors) The crappiest steel yields at 36,000 psi.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 23, 2010 - 09:52pm PT
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Most certainly the split shafts are stronger in both sheer and pull-out.
I contended that the Z is a good tool of the FA'ist to move quickly through a ladder section. Placing bolts here and there.
As a body weight piece, used only for progression not protection.
Not to mention that pulling them does not ruin the integrity of the hole.
Easy to remove and replace on subsequent ascents.
Thanks for the tests, Now what if I sent you a brand new 1/4 star drive?
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'Pass the Pitons' Pete
Big Wall climber
like Ontario, Canada, eh?
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Oct 23, 2010 - 09:58pm PT
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Wow. I can't believe the quarter-inch stainless expansion bolts are that strong. I thought they failed at around 1200 lbs.
Can you do the same test please on a 1/4" Rawl buttonhead rivet, the kind ASCA supplies us with? I thought those things were good to a couple thousand, and were substantially stronger than the expansion bolt.
At first, this seems counter-intuitive, until you examine the expansion bolt up close, and see that at its narrowest it is rather thinner than a quarter-inch.
Cheers, eh?
Speaking of big-ass levers, Tom used one to test his Valley Giant 9" cam to failure at over 5000 lb, hugely stronger than any commercially made cam.
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Greg Barnes
climber
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Oct 23, 2010 - 10:56pm PT
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Email me your mailing address, I'll send a few 1/4" buttonheads, short and long (1.25" and 1.5"). And maybe a couple of the 1/4" Hilti coil bolts too! Email is greg@safeclimbing.org.
Fun tests!
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Oct 24, 2010 - 09:52am PT
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I can do more testing but it does take time. I need to quit hand drilling and get out my old rotohammer. Also, the little green load cell in the photo above is only rated to 2000 lbs. Most load cells are reasonably accurate to 1.5 rated and won't be damaged until 2.0 but it isn't a good idea to go over. I thought the 1/4 SS would break at less than 2000 lbs and once started, it's hard to stop.
I do have a perfect 10,000 lb load cell but it needs a base plate. I can't use it until I can cajole a machinist friend to make one. Basically a 3-3/8" round by 1-1/4" thick with 9 drilled and tapped holes in it.
Greg, check your email.
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Clint Cummins
Trad climber
SF Bay area, CA
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Oct 24, 2010 - 07:23pm PT
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Nice, Dan.
I didn't know there was anything stainless 1/4" that was good, but that 1/4" wedge is pretty strong! Maybe an option for 1/4" aid ladders.
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Mungeclimber
Trad climber
sorry, just posting out loud.
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Oct 24, 2010 - 07:28pm PT
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This is a 1/4" inch in diameter?
nevermind, I guess it is as I look at it longer.
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Strider
Trad climber
one of god's mountain temples.... ಠ_ಠ
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Oct 24, 2010 - 08:09pm PT
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I have a few bolts you can try and break if you like and am more than happy to ship them off.
I have (2) 8mm Fixe rivets. These are the ones that are NOT recommended by Greg B. and I have found they SUCK big time. When you try to drive them into the hole they tend to bend rather than go in. You're welcome to break them though... Need the correct sized drill bit though for the hole...
I have (100) 1/4" split shaft rivets I bought that I would be happy to donate a few. I have a placed more than few of these and never had any problems.
-Nick
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cragnshag
Social climber
san joser
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Oct 27, 2010 - 07:12pm PT
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The 1/4" wedgies are made by Simpson. By the way, they are 316 stainless and very tough- as shown in the results above.
Plenty strong for an aid ladder and perhaps even for pro bolts/ belays on remote slab climbs where you will not be able to generate 2000 lbs on the anchor.
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bwancy1
Trad climber
Here
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Oct 27, 2010 - 08:00pm PT
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Interesting.
You are pointing out the relative "strength" between the two bolts. The fixture appears to be measuring neither shear, nor tension ("prying" as you noted.)
Did you calculate the reported tensile (pullout) strength based on the geometry, etc., or are the numbers that you published simply the force exerted on the fixture at failure?
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Acer
Big Wall climber
AZ
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Oct 27, 2010 - 08:38pm PT
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Always fun times in the shop.
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Captain...or Skully
Big Wall climber
Transporter Room 2
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Oct 27, 2010 - 08:53pm PT
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I can feel the techno-geek AND the Wallclimber attraction to that action.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 27, 2010 - 09:59pm PT
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mucci- Before you get too excited about those zinc anchors remember that the steel cabled rivet hangers are going to wear through the softer body of that sort of anchor faster than a solid steel anchor. It would be interesting to cut into the top half of one down to the steel drivepin to see how that effects the holding power in direct downward shear.
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Mike Bolte
Trad climber
Planet Earth
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Oct 27, 2010 - 10:07pm PT
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interesting, thanks. I don't quite understand your set up from the photos.
tomtom - archimedes' principle is about the buoyancy of a fluid.
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couchmaster
climber
pdx
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Oct 27, 2010 - 10:28pm PT
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Awesome! The mantle of Ed Leeper is falling on your shoulders. Thanks!
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 27, 2010 - 10:47pm PT
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Steve-
I do agree that a zmac would wear faster than a split shaft buttonhead. However, In regards to the "Traffic" diminishing the sheer strength of a zmac...
Sure after 10 ascents I could see a replacment being needed. Now, If I am on a new route, and place these rivets, I am cutting the drilling time down significantly. That is where they shine, not everthing on a wall needs to be "Protection".
On that same note, it is not the FA's responsibility to outfit the route for the safety of the future teams. If that were true bathooks would be filled with bolts...
Not to mention, getting a repeat of a route in the valley or elswhere is damn near impossible (outside of your friends). No traffic to worry about.
Pretty much the easiest rivet to remove and replace. No one is disputing that.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 27, 2010 - 10:55pm PT
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I am still a stainless machinehead booster. Is a 1/4" hole that is a 1/2" deep really too much work for you?!?
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 27, 2010 - 11:01pm PT
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Ok Steve, we should go see which rivets pull without damaging the rock.
You create USELESS holes with machine heads.
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Oct 27, 2010 - 11:16pm PT
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Excellent, another thread about bolts and ideas for bolt ladders! The split shaft are bomber and for a bolt ladder they have applications, but the 1/4" SS wedges are way strong based on that one test! Those SS 1/4" wedge anchors would be nice while on some 5.10+ runout freakshow friction slab hand drilling, calves cramping while your toes turn blue!!! I always liked the Red Head 3/8" self drilling bolts BITD for friction routes, then you do not need a drill....But I always brought extra in case I broke a tooth, then top it off with a SS cap bolt and SS hanger and your golden!
The problem with the self drill is the size of the hole once the bolt needs to be replaced. It is possible to drill out the center wedge with a high speed 3/8" drill then the Red Head can easily be pryed out. But then you would need to place another Red Head self drill or fill the hole with glue/granite?
just typing out load,
Thor
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'Pass the Pitons' Pete
Big Wall climber
like Ontario, Canada, eh?
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Oct 27, 2010 - 11:22pm PT
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I remain amazed at the apparent strength of the 1/4" expansion bolt. It just doesn't seem possible. Look at the bloody thing closely sometime and you will see how skinny it really is in a few places, because of the threads cutting into the shaft and the cone thingy and so on.
Accordingly the Rawl 1/4" buttonheads should be hugely stronger. Or am I getting excited about a single test that might not hold up when replicated? I think you need to bust a few more bolts, mate!
Greg, explain to Steve why machine bolts are no longer cool.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 27, 2010 - 11:27pm PT
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Steve already knows.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 12:21am PT
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Do what you like...the cabled hangers should break before a properly placed machinehead fails. Shallow anchors aren't really intended to hold long falls so the last hole in the ladder should be a larger bolt and hanger to keep the installation intact. I usually place a smaller diameter stud with a keyhole hanger every fourth or fifth hole in a ladder to keep the tear out potential low.
If a machinehead actually pulls out then upgrade to a slightly larger machine bolt to replace it...but then what do I know???
Pete- Greg isn't your mouthpiece so provide the explanation yourself if you think that my methods are "uncool," as you put it.
How much ladder drilling have you estimable gents actually done?
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 28, 2010 - 12:50am PT
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Steve,
All this talk about falling on rivets and breaking hangers is absurd.
No way you are gonna fall whilst drilling a rivet ladder.
So you are thinking about the future teams again?
Early ascent teams should think it prudent to bring a drill kit.
Edit: Hey steve, how do you reuse a hole when there is a stud with no head?
If you try and remove a machine head, the rock comes with it.
You should know this.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 12:55am PT
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I am not worried about falling while I am drilling a ladder. With rivet hanger failures being fairly common for a wide variety of reasons, sustainability for subsequent parties is the issue.
Why not do the best job that you can on the FA?
I have been placing 3/8" bolts even on desperate stances for decades with the next climber in mind. Too freakin' bad that 3/8" split shaft Rawlbolts are garbage because I have placed a lot of them in vain.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 28, 2010 - 12:59am PT
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Oh, and on the few ladders I have been a part of, we used 1/4 in bolts with hangers every so often, just like you.
For the middle, the z's go by pretty quick.
I am not concerned about future parties, just my own ass at that particular moment in time.
Edit: Yes you have drilled big bolts, and you have unrepeated routes.
Fact is, there is a good 20+ years that need to go by before most modern NEW routes get a repeat. By then ALL of the metal is suspect.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 01:01am PT
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Your last sentence says it all...
If any anchor shears off then your options are clearly limited.
Stainless steel machineheads should have a very reasonable service life exceeding 20 years easily. I would have never placed any mild steel bolts or machineheads BITD had I known what I know now.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 28, 2010 - 01:06am PT
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Steve....
I drill 3/8 SS at the belays if needed.
there you go again with the doomsday critique.
We are talking about rivet ladders here.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 01:08am PT
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"Doomsday critique?!?" Please...
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Greg Barnes
climber
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Oct 28, 2010 - 01:11am PT
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The manufacturer data says that stainless 1/4" studs would generally snap in shear around 1500 lbs, not 2500. That's the performance data on the Powers stainless studs, I could see the Hiltis being better but not that much better. The powers ones are stronger in tension so the testing methodology may make a difference, and of course the sample size here is one.
We got a box by accident one time and they didn't want to bother shipping them back, so I gave them away to a friend. Actually used a couple to bolt down a drainpipe.
Buttonheads are stronger in shear (around 2000 lbs), and removable - the studs will snap if you try to remove them.
As far as the machine head debate, I know basically nothing besides 2nd and 3rd hand opinions. The only ones I've replaced have been at free climbing anchors, and they popped super easy. Some cratering but it didn't matter since I was drilling them out to 3/8" anyway.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 28, 2010 - 01:12am PT
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If any anchor shears off then your options are clearly limited
Sounds grim.
Now if you had read my post you would have noted that not EVERY placement is a rivet...
The last tends to be a bolt. Just like you steve, you know to prevent that huge fall off of the rivet ladder.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 01:17am PT
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I did read your post and made no such assumption.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Oct 28, 2010 - 01:17am PT
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One test isn't worth much but it does give an indication. I usually say that I need at least five to make a reasonable probability statement *IF* the data isn't too scattered. This would take a lot of time to achieve with so many variables.
The test wasn't shear or tension but some combination approximating a hanger loaded parallel to the face and down, (I actually loaded up) the proportion of shear and tension could be figured out from the 4th photo by applying a little statics (did I tell you I'm teaching statics this semester?).
The red ram is hollow and the threaded rod runs from the green load cell through the ram to a nut.
One variable none here has mentioned is the rock. The piece I have is pretty hard. Hard to quantify how hard.
So it sounds like people want about 6 types of 1/4" anchors tested. We need 5 in shear, 5 in tension and maybe 5 kinds of rock. If the data scatterers, we better do twice that. so:
6x(5+5)x5x2=600 tests (check my math for me, I'm sleepy)
Then we need to add some corrosion variables including limestone, salt, the various metal combinations.
I think I need funding.
As far as the zinc POS goes, I think a full size climber (Mucci what do you weigh, 180 or more? We met once and I forgot to weigh you) could pop one with a 1 or 2 foot drop in stirrups. Might be able to break one with a couple solid bounces - but probably better than bat hooking.
Cripes, I type too slow to keep up with you guys. I'm going to bed.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 28, 2010 - 01:22am PT
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I guess we are on the same page then Steve.
both of us are worried about rivets so we place bolts every so often.
The longevity of any placement is not likely calculated.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 01:24am PT
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I would love to actually know what those 5/16" X 3/4" stainless machineheads hold when loaded in shear. The Grade 5 machine bolts that I used to use are a bit stiffer than the readily available stainless bolts.
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mikeyschaefer
climber
Yosemite
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Oct 28, 2010 - 01:34am PT
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Fact is, there is a good 20+ years that need to go by before most modern NEW routes get a repeat. By then ALL of the metal is suspect.
Not to mention, getting a repeat of a route in the valley or elswhere is damn near impossible (outside of your friends). No traffic to worry about.
Not sure about your facts. All of the routes I've established (except one where no bolts were placed) in the last 5 years have seen repeats (or attempted repeats) in Yosemite. Even by people I don't know.
I've been placing 1/4" split shaft on lead and then pulling and filling with SS 3/8". But I do care what the second ascent teams experience is. I take a fair bit of pride in establishing a route that can and should be repeated.
If I had left the holes as 1/4" I bet the routes wouldn't of been repeated. That would suck.
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mucci
Trad climber
The pitch of Bagalaar above you
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Oct 28, 2010 - 01:34am PT
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Might be able to break one with a couple solid bounces
First one I placed, I jumped up and down so hard I hurt myself.
I have also hauled and jugged on a series of 10 year old 3/4in Zmacs with a machine head and buttonhead thrown in for good measure.
No Danger.
Edit: Mikey-If I had left the holes as 1/4" I bet the routes wouldn't of been repeated. That would suck
Jesus are you serious???? Kinda picky teams wouldn't you say?
I want the SA team to get a good route, and by placing zmac rivets on a line does not transform the route into a death show.
Reclimbing a big wall and replacing all the hardware to 3/8 is something I would never do. All the more power to you.
Edit: Mikey I was refering to Wall routes, now that I read your post, I believe you were talking about free routes? In which case I agree 100% in replacing 1/4" hardware placed on the FA with 3/8ths.
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bhilden
Trad climber
Mountain View, CA
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Oct 28, 2010 - 02:46am PT
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Thorgon,
I am not too keen on any of those self drives for the simple reason is that you drill a 3/8" hole then screw in a threaded 1/4 bolt to attach the hanger. That seems like a lose-lose situation in that you have to drill a 3/8" hole, but you end up with a 1/4" bolt. More time for less strength doesn't seem like a good trade-off to me.
Bruce
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Oct 28, 2010 - 09:49am PT
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Good morning knuckleheads!
Some have expressed surprise at the strength if the 1/4" SS wedge anchor but it doesn't seem unexpected to me because of how strong granite is. PLEASE NOTE that my quarried piece has not weathered and may be stronger than what you would typically find in the wild.
Anchor strength is limited by the bolt strength or the stone strength. The values published by bolt manufacturers are based on concrete strengths, usually compression strengths of 2000 to 4000 psi. This is typical construction concrete. High strength concrete can be 10,000 psi.
The tensile strength is also of interest. Engineers seldom test for the tensile strength of concrete because we generally assume it is zero in anticipation of cracks (did I tell you I sometimes teach design of concrete structures?). It is sometimes measured using a small beam (I've done this a few times) but the test is usually more trouble than it is worth. A more common cylinder splitting test results in the "Modulus of Rupture" (I've done this many times, it's cool how it works) which is larger than but related to the tensile strength. In actual practice, engineers usually just estimate the modulus of rupture as being the square root of the compressive strength times something between 3 and 8. I think the ACI code suggests 7.5(fc')^0.5 which results in:
Modulus of rupture for 2000 psi concrete 335 psi
Modulus of rupture for 4000 psi concrete 474 psi
Granite is a different material, good granite is much stronger than concrete and can have very high tensile properties. After doing a little research, I found a very cool old book in which the state of Wisconsin published material properties of stone from various quarries. Google "On the building and ornamental stones of Wisconsin" By Ernest Robertson Buckley, Wisconsin Geological and Natural History Survey, 1898. PDF versions available. On pages 390 and 391 they list the crushing strength of quite a few granite samples. They also tested a few for modulus of rupture with results on page 396.
Quarry granite compression strength 15,000 to 47,700 psi
Quarry granite modulus of rupture 2,700 to 3,900 psi
This indicates that for granite, the modulus of rupture is something like 300 to 500 times the square root of the compression strength. Granite is proportionally much stronger in tension that concrete.
I hypothesize that the shear strength of a split shank buttonhead will be very high since they are hardened steel. Greg Barnes sent me a few and when my load cell is ready, I'll publish some results.
You guys quit hypothesizing regarding topics about which you are ignorant.
"People who know only a little do not understand
how little they know and are therefore prone to error."
Alexander Pope.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 28, 2010 - 11:35am PT
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The issue with split shaft anchors used in climbing applications isn't their strength when newly placed. They are plenty strong enough out of the box. Once water and time enter the equation then strength begins to diminish as the heavily stressed metal at the split point corrodes and fractures due to hydrogen embrittlement and other deletarious forms of accelerated oxidation.
Tortured metal does not make for good and lasting anchors. Use stainless steel and do everyone a favor!
As mentioned upthread, try your best to select a fastener that yields a bearing cross section that matches the hole diameter especially at the point of applied load from the hanger.
Greg- are you guys still using wedge anchors as the bolt of choice for your activities?
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bhilden
Trad climber
Mountain View, CA
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Oct 28, 2010 - 01:29pm PT
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Greg can answer Steve's question directly, but the bolts Greg sends me for my ASCA rebolting work have always been 5-piece Rawl (now called Power) bolts.
Bruce
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Majid_S
Mountain climber
Bay Area , California
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Oct 28, 2010 - 09:19pm PT
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The angle iron act as lever and its obvious that the red head will come out like that. why not try it with a real hanger and see what happens
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Greg Barnes
climber
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Oct 28, 2010 - 10:51pm PT
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Greg- are you guys still using wedge anchors as the bolt of choice for your activities? No, we haven't used stud/wedge bolts in many years (with rare exceptions). They are not removable for future rebolters. I'd say about 90% of our bolt use is 5-piece (Power-Bolts) in various sizes and lengths, 5% Fixe Triplex, and 5% glue-ins.
We do sometimes use 1/4 x 1.5" buttonheads plus washers for rivet replacement on walls. "Too bomber" is an occasional complaint, but they are removable.
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Clint Cummins
Trad climber
SF Bay area, CA
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Oct 29, 2010 - 12:20am PT
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Dan,
Sorry if my post suggested I was skeptical about the strength of the 1/4" SS wedge bolt you tested. What I meant was that I was pleased that you had informed me that there was 1/4" SS which was good! I had not previously heard of anything 1/4" SS that was very strong, so it is helpful to know about this option. (Although I drill 3/8" for my own climbs and for replacement, and recognize that drilling 1/4" splitshaft on lead and replacing with 3/8" is also good).
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cragnshag
Social climber
san joser
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Oct 29, 2010 - 12:59am PT
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OK professor, get out your hammerdrill. I've got plenty more 316 SS 1/4" wedgies for you to test. Better they get some use in your experiments than collect dust in my garage. I don't foresee any remote big walls in my future before little buddy hits grade school age... I'll bring some by on may way home from work.
Make sure to make the lip of the hole is a little cratered to simulate hand drilling on weathered rock. I bet they are stronger like this (combo shear and tension when bolt bends slightly at the lip) than with a sharp lipped hole where shear would be predominant. I took a picture of a newer button head (recycled, of course!) alongside the wedgie to give folks an idea of just how tiny these bolts are.
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Steve Grossman
Trad climber
Seattle, WA
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Oct 29, 2010 - 12:23pm PT
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Concrete screws are right out...don't even go there.
Greg- Glad to hear that you guys are not using wedge anchors anymore. I have another fastener system that may interest you that is much cheaper than Powers 5 piece. I have a small amount of testing still to perform myself.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Oct 29, 2010 - 04:24pm PT
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Bad day of testing today.
Greg Barnes sent me some 1/4" anchors of various types to test and I got a 5000 lb load cell working so I thought I'd goof off and test a few. I decided to quit hand drilling since none of you offered to come over and make holes so I got out my old roto-hammmer. It's a little big for a 1/4" hole but I figured it would at least go fast. I set it up and drilled a hole - it was like drilling in wood. took all of about 30 seconds. I started a second hole and my bit skittered on the face and blew out the carbide. I don't have another 1/4" bit so resigned myself to one test for today.
I picked a 1/-1/4" button head and whacked it in with my hammer. The surface of the stone flaked and spalled a bit and I trapped some rock junk between the plate and the face of the rock. Oh well, so it goes.
I loaded it up but my test fixture failed before I actually popped the anchor but the anchor was loose in the hole and I pulled it out with my fingers.
I also bent the SS shackle just enough to make it worthless, there goes another 4 bucks. I've been spending too much on shackles, threaded rod, drill bits, coupler nuts and load cell accessories. I am pretty sure I won't be turning a profit on this project.
Anyway, I got to 2715 lbs.
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Minerals
Social climber
The Deli
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Oct 31, 2010 - 01:57pm PT
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2,715 lbs from a shorty and people still bitch about quarters???
Cool testing, Banquo! In the last photo, did the bolt begin to crack, on the convex side of the bend? How about testing the 1.5” length? And, how about testing some of the Fixe 8mm crap bolts (or do we really want to know…)?
As was mentioned earlier, testing the bolts with a real bolt hanger seems more appropriate. Also, it’s a good idea to “pre-crater” a quarter-inch hole before hammering in a buttonhead. I use the pick end of my hammer to flare out the hole a little. This helps to prevent any cratering and accumulation of rock chips behind the hanger during bolt placement.
Too bad you’re not just across town… I’d come over and drill holes in that block all day long for ya… with a real drill bit! ;) Keep up the good work! Thanks!
Re. ASCA and those wedge bolts that I hate so much… We actually placed a few stainless shorties this year, as replacements for Bachar taper bolts. It is easy to remove the taper bolt itself, but then the soft sleeve is stuck at the bottom of the hole, which would require power to remove. So we just tapped the sleeve to the bottom of the hole and then placed the wedge bolt. No, it’s not removable, but we were able to reuse the original holes. A stainless 5-piece would have required a new hole, so why not utilize the existing hole while we can? Someone can drill a new hole in 100 or 200 years.
(Hey Al Dude, One-Armed Bandit has been replaced…)
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Clint Cummins
Trad climber
SF Bay area, CA
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Oct 31, 2010 - 02:12pm PT
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Bryan,
> It is easy to remove the taper bolt itself, but then the soft sleeve is stuck at the bottom of the hole, which would require power to remove.
Just like the Star-Dryvins, I believe you should be able to remove the lead sleeve with a lag screw.
But I'm not sure - I have done it many times for the Star-Dryvin, but not yet for a taper bolt.
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Minerals
Social climber
The Deli
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Oct 31, 2010 - 02:25pm PT
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Good idea, Clint. I had some lag bolts that Greg gave to me in order to remove the lower sleeve on a 6-piece bolt but I had no luck with this method. It might work better with something soft like the taper bolt sleeve – have to give that a try. Thanks!
I think we need to get with Theron to design a specific sleeve puller for the 6-piece bolts. I have yet to get the lower sleeve out on one of those longer bolts. Damn power drills…
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Oct 31, 2010 - 02:36pm PT
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Bruce~
The hole is actually bigger than 3/8" and the the cap screw is 3/8" and using stainless steel cap screw makes for a great set up. If I can dig out my old hand drill I will post a picture. It is basically a piece of solid steel round stock with a 3/8" tap in one end where you place a 3/8" stud with a locking nut. Then you attach the Red Head and tap and turn till your calves burn! I used this set up on one of my FA's in North Caroliina at Stone Mtn., then the Carolina Climbers Coalition came through four years later and removed all the hangers on my bolts and placed SS bolts next to them, really made a mess! I understand that they wanted the routes to be safe, but it seemed like a waste of my efforts to place good bolts in the first place! Do not get me wrong CCC has made climbing safer in the South for years, I just wonder about a better way to replace self drilled anchors!
I am drifting, hope that explains the Red Head self drillers I used in the early 90's. So the question is can the hole be reused instead of just filling it with glue & granite dust? Anyone? You can drill out the center cone, but I never have measured the I.D. of the hole to see what size it is, could you drill deeper and place a SS expansion bolt, no b/c then the top of the hole would be to big, glue-in? I don't know? Like I said it is the best set-up I have ever seen for hand drilling, but the replacement issue has always bothered me. This self-drill set-up may have good wilderness back country applications?
By the way, I was using hardened steel (machine grade V, I believe) hex head cap screws in North Carolina, it was the early 90's and no one was using SS at Stone Mtn at that time! I also used Lock-tite and silcone under the hanger, which I think helps on friction routes b/c water tends to fill the holes.
Thor
GREAT THREAD! BOLTS, YEEHAW.....
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Steve Grossman
Trad climber
Seattle, WA
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Oct 31, 2010 - 10:48pm PT
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Time to pass the hat...the man is spending all his shekels on shackles! LOL
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Oct 31, 2010 - 11:07pm PT
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I could send $10.00.... Better cause than the TV Evangelist!! LOL
Thor
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bhilden
Trad climber
Mountain View, CA
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Thor(gon),
your are not scoring any points with me with your explanation. As you state, you have to drill a hole larger than 3/8" to insert a 3/8" threaded cap screw. That is a lot of extra work for a 3/8" bolt. Why?
Another issue is that threading something, unless it is done correctly, adds a weakness to the stock which is threaded. If you look at the photos of the Simpson wedge anchors in this discussion, you will notice that the threads are not cut into the stock. The threads are on the outside of a round piece of stock so there is no chance of adding a stress riser.
Cut threads, on the other hand, add a stress riser to the stock and weaken the screw. All the cap screws I have seen use cut threads.
So, you have to drill a hole larger than 3/8" to be able to insert a cap screw with cut threads. That's two strikes in my book.
The third strike is that, in my experience, it takes more than one self-drill anchor to drill one hole. That's a lot of waste and weight.
Bruce
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Bruce,
It has been my experience that hand drilling sucks no matter what drill you use. But that is how I was raised, ground-up hand drill, I have a Bosch but only use it for replacing bad bolts! I have replaced a lot of bolts and can tell you that if the hole is over-sized the whole operation is a shame (which I am sure you know). The upper bolts on Yankee Go Home Stone Mtn NC were "replaced" by an old timer and we ended up with spinners! When I went to replace them a second time it only took one or two taps with the hammer to remove the "new" bolts because the hole was oversized. I have used every hand drill that is available and I like the Red Head system for remote routes! However, I think it is a non-issue because I checked the Red Head website and they don't sell the self drive anymore. So let's just forget the entire issue!
Back to your regularly scheduled program: "Tested two 1/4" anchor"!!!
Thor
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Clint Cummins
Trad climber
SF Bay area, CA
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Cool old gear, Thor. Hand drilling is not too bad with the SDS carbide tip drills. The Petzl RocPec SDS holder is also a lot lighter than the self-drill setup in your photo. :-)
I agree, it sucks if somebody tries to replace your bolts, but does a bad job and they end up worse than the originals!
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Clint,
Hell yeah the SDS's are nice, I started with a star drive masonary drill and still have the scars on my calves to prove it! Three hours on one hole at one 5.9 friction stance, then I gave up but my calves cramped so bad I still have the bruises! My dad had a Bosch Bulldog that he would not let me use, actually I wouldn't have used it anyway, but we decided to call the route "Father Knows Best"!! That was about 1990' then I got a bunch of the old 5.10 drills with the double straight flute and they worked o.k and I finished the route on my 27th birthday! But once the corners chipped off of the 5.10 drills you were dead in the water! My best time is still 1/2 hour and that was when I was doing it all the time and not just typing about it on a computer! LOL
It was that 1/4"x 1 1/4" deep hole to 3/8" x 2 1/4" deep hole transition of the early 90's that took some getting used to for sure! The 1/4"ers you could just bang out and slam in a Button Head and move on, but to drill 2 1/4" of 3/8's in GRANITE, then you were a working man!!!
Send On,
Thor
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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This is all some really cool info. I'd really like to see more of this kind of testing.
If money is an issue to keep the testing going I'm sure Supertopo can help out with that. I'd be willing to donate some SS SMC hangers, Metolius SS hangers, 1/4" x 1 1/4" button heads and even a bit of cash.
I also have some 1/4" x 2" "spikes" that I'd like to see tested. I've had alot of people tell me those are total crap. But in my (limited) experience pulling them, they have been the hardest 1/4 in bolt to remove.
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mucci
Trad climber
The pitch of Bagalaar above you
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I agree 100% on the 1/4 spike bolt, very hard to remove.
Never placed one though. Would love to see one of those pulled.
SAL-
I will buy those SS SMC hangers, what size hole? Buttons or threaded?
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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Those SMC hangers have a 1/4in hole. Buttonheads wont work, which is why I want to see the spike bolts tested, among other reasons.
If it turns out I can't use them for anything, you can have em'. I'm not placing 1/4 in wedge bolts for lead anchors (just don't trust them) and I don't think I'd use them on a bolt ladder, so....
Whatcha gonna use em fer?
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mucci
Trad climber
The pitch of Bagalaar above you
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Drill em out and use them on the lead.
Are they the fat ones, 3rd generation? I placed a 1" buttonhead with one of those fat SMC SS hangers, Fully bomber. I would kill to get a bunch of those with the 5/16ths hole.
The 1/4 inch hole SMC hangers that are black oxide are a newer generation as well, highly coveted by the 1/4" driller.
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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Yeah, newer generation fatties. Those hangers are bomber, you just can't push a 1/4in buttonhead through that 1/4in hole. Spikes will work though. I was thinking about drillin em out. No vice or drill press though.
Got em off Back in Black at Sugarloaf when I replaced the bolts.
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mucci
Trad climber
The pitch of Bagalaar above you
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I can drill them for you, just let me know.
That combo (1/4" x 1.25") w/ SS Smc is the best on lead.
Banquo- give us a list of what you want to test, I have loads of 1/4 gear, along with some very weird expansion bolts.
1/4" Spike bolt
Threaded 1/4 split shaft
Short buttonheads
Wedge and expansion
star drives :O
We should just have a shop day, I will bring the beer.
Mucci
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 4, 2010 - 11:50am PT
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I got some new 1/4" drill bits in the mail yesterday. Don't be sending me boxes of junk to test, I have enough stuff lined up to test for now. As far as costs go, the equipment is the expensive part. I'll be checking the front porch to see if anybody has donated a battery powered hammer drill or perhaps a couple of these:
http://www.futek.com/product.aspx?t=instrument&m=usb210
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mucci
Trad climber
The pitch of Bagalaar above you
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Mucci, double drilling in the death spike chimney?
HAHAHA!! You have a good memory BES...
No drilling but that biner link is pretty cool.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 4, 2010 - 06:56pm PT
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My machinist friend was going to make a base for the 10 kip load cell but has now said he can't get to it - he is going in for back surgery and will be laid up. So, I'm limited to 5 kips until I can get one of these made:
http://fci.thomasnet-navigator.com/ACOTemp/Geomstore/20101104-183526-21628295.pdf
Think I'll call the company and see what they cost first, I'm guessing $100.
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adatesman
climber
philadelphia, pa
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If you get stuck Banquo I could whip that up fairly easily. I'm not exactly local to you though, but oddly only 2 miles from the company the blueprint you linked is located (West Conshohocken, PA).
BTW, I sent you a PM a while back about gear testing and just realized yesterday that the email in my ST profile was no good. It's fixed now, so let me know if you're interested (or have no idea what I'm talking about).
-aric.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 5, 2010 - 01:08am PT
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I stayed a bit late tonight and turned out the piece in the lathe while the tech wasn't watching his shop. I'm about half done making it myself so no problems with that. Turned the disc and got the center hole drilled and tapped. Been a long time since I pretended to be a machinist. Weird thing is I've spent about about as much time doing this as I spent talking to the other guy about it. Just do it often seems the best option. That's why I don't have employees ... I can probably do most things in less time than I can splain it to some other bonehead.
I can measure drop forces but somebody needs to find a 50' drop which is harder to find than you might think. Somebody needs to donate ropes, etc. Also need to predict forces, frequencies, etc. so we can have the right instrumentation. The object you drop is important too, an iron pig will get different results than a sack of meat. Meat sack natural frequency is probably 10 Hz or less - I can easily document to 10 kHz.
adatesman - I responded to something about a test data website archive but didn't hear back so sh#t canned everything. I give up pretty fast on such things. I hope somebody archives my data because I don't.
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Greg Barnes
climber
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Yeah, newer generation fatties. Those hangers are bomber, you just can't push a 1/4in buttonhead through that 1/4in hole. You don't need to drill them out - just take a rattail file and a minute or two for each hanger. Easy to do at camp too. I make the holes into oval shaped slightly-less-than 5/16", with the long ends to the sides so there's less play up and down, works great. Check with a buttonhead to make sure you don't oversize the hole - and if you have various buttonheads (eg 1.25 and 1.5"), check with one of each since they aren't always the same width.
If you do use a rattail file, it can help to use vice grips to grab the hanger since there's not much to grab with your fingers.
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bhilden
Trad climber
Mountain View, CA
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As Greg suggested, use a file to slightly enlarge the hole. A tip from Paul Piana, files for sharpening the chains on chain saws are pretty cheap and work great.
Bruce
ps- I rebolted an anchor in Boulder Canyon that used 1/4" Rawl spike bolts. The rock was granite and the holding power appeared to be about the same as a split shaft.
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Greg Barnes
climber
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The 1/4" spikes that pulled SUPER easy were the stainless ones, Minerals was looking into those as possible stainless replaceable rivets for walls.
But I wouldn't trust spikes in general since they would be sketchy if the rock got even slightly grainy - I pulled a 3/8" one by hand in grainy Joshua Tree rock.
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Banquo,
That site you linked up thread should be called FUKET for $500.00 USB210 external kit! That is a lot of drills and bolts, man! Keep up the good work, we place bolts to save our butts and don't always know exactly how they preform in the real world! Insightful testing is the key!
Thanks,
Thor
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 11, 2010 - 10:46am PT
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I did two pullout tests. The first a 1/4" coil bolt Greg Barnes sent and the second a 1/4" SS wedge bolt Cragnshag gave me.
I drilled a 1/4" hole and screwed the coil bolt in but it stopped before it snugged up. I decided to keep going and see what would happen - probably exceeding the 10 ft-lb installation torque. It just turned in the hole but didn't tighten up. It had stopped when the shoulder where the threads end reached the rock face and about 3/8" short of being tight. I thought about what to do and decided that if I was climbing, had to use it and this happened, I would just pound it in so I did that. It pulled out at 1060 pounds. When I screwed it in. the coil had stayed near the face of the rock and jammed against the shoulder. I think these bolts would work better in concrete which is no where near as strong as my granite.
The hole being undamaged, I knocked in a 1/4" SS wedge bolt and snugged it up. The wedge was below where the coil ended up in the previous test so I felt it was essentially in a virgin hole. This one snapped at the threads at 3460 pounds. The net section at the threads must be smaller than the net section at the wedge or maybe the stress concentration is higher at the threads. Still, 3460 lb is an impressive result.
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Greg Barnes
climber
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Nov 11, 2010 - 11:01am PT
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Cool Banquo, that's the sort of thing that is really important for climbing - messing up the installation completely!
I got those coil bolts from Norman Boles, but I haven't tried any since they are even longer than long 1/4". Hopefully Norman will chime in if he got a chance to try any of them.
That's an amazingly high result on the stainless stud bolt. Of course no one tries 1/4" bolts in pure pull-out (unless someone uses them for horizontal roof bolt ladders), but still...
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 11, 2010 - 02:04pm PT
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Greg-
Well, I'm not so sure I messed up the coil bolt installation. I drilled a very nice, clean, straight, deep, 1/4" hole with a brand new drill, the bolt simply wouldn't go all the way into it. I am a bit puzzled about how they expect the coil to work. Is it supposed to stay near the tip of the bolt or near the surface? It seems odd that the bolt is so long if the coil is going to end up at the top of the threads which means the bolt only contacts the sides of the hole near the surface. What got stuck was the little tab that sticks up from the top end of the coil, it ended up pressed against the shank above the threads.
A coil might be a useful design as a temporary connection used with a permanent adhesive.
As far as messing up goes, when the SS bolt popped, the rig fell apart and knocked the digital display off the work bench. It landed on the floor and seems to be dead now. Omega DP41-S list price $545 plus shipping and tax. Ouch! Oh well, spilled milk. I'll go through my junk boxes and see if I have a signal conditioner I can use with a voltmeter for a display. The good news is that the 12 year old unit didn't cost me anything in the first place as it was given to me by a colleague who retired. Don't think I'll replace it though. I see one on ebay today for $499 WTF are people thinking?
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cragnshag
Social climber
san joser
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Nov 11, 2010 - 03:26pm PT
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You have totally ruined that nice granite block. I hope you plan on patching all those holes when you're done.
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Greg Barnes
climber
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Nov 11, 2010 - 07:02pm PT
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Maybe the hole needs to be 17/64" if it's in good granite (instead of concrete). That's the size HSS bit that you use with 1/4" buttonheads. Those seem to drill the same size hole that hand-drilled 1/4" SDS bits produce. But I'd check the Hilti coil tech docs first...
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 12, 2010 - 08:57am PT
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I see the problem, the Hilti installation instructions do call for a 1/4" bit but also say that the minimum fixture thickness is 5/8". Somehow I missed that when I looked at it before the test. I guess that means you would have to enlarge the top part of the hole to use them. A stack of washers would work but I don't like the idea.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 23, 2010 - 11:51am PT
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More 1/4" Button heads, this time a couple 1-1/2" ones. Above, Greg says a 17/64" (0.266") hole and the Fixe web page says 8mm (0.315").
http://www.fixeusa.com/button_head_bolts.htm
Confusion reigns. Perhaps 5/16" (0.313") is the answer. Digging through the drawer of old drills, I found a 17/16" HSS bit and ground it down on the belt sander. Holding it with vice grips, it drilled surprisingly well if kept sharp. However, it tended to get stuck, got dull pretty fast and the tip chipped a little.
First a pullout test, 630 pounds
Then a shear test, I got 1130 lbs which is less than half of the 2715 lbs that I got for the 1-1/4" button head. I think the main thing to remember about button heads is that their capacity is unpredictable and highly dependent on condition of hole, quality of rock, condition of rock face, etc. Most of which you can't assess when installed. In this case, it looks like the rock face spalled when I started loading and the button head bent over at the top of the split where it then tore off. Capacity may differ depending on load direction in relation to the orientation of the split.
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Juan Maderita
Trad climber
San Diego, CA
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Nov 23, 2010 - 11:05pm PT
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Confusion reigns. Yes, and it is difficult to interpret what you might be thinking. Perhaps your confusion is that two diameters of buttonheads are sold on the Fixe website.
FixeUSA sells 1/4" Powers "Drive" (formerly "RawlDrive") buttonheads and also Fixe 8mm buttonheads.
The 1/4" Powers should be drilled with a 1/4" bit. Some people start the hole with a side-to-side slop to oval the entrance of the hole. Place the bolt in the hole with the split in a horizontal position before hammering. This prevents excessive spalling. That seems particularly beneficial with the 8mm and 5/16" buttonheads.
The Fixe 8mm should be drilled with an 8mm bit. 8mm is slightly larger than 5/16". The Fixe buttonhead is particularly soft and likely to bend, more often than not, when driven into a 5/16" hole.
I don't understand why you are messing around with different size bits. Why not just use a rotohammer with SDS bit and be done with it in 15 seconds?
The low numbers you got on the 1/4" x 1.5" are suprisingly low. Something seems off about that. Perhaps the poor result has something to do with the hole being drilled 1/64" too large? Or a problem with the test equipment? Can you repeat the test and get similar results?
I'm also curious if there is a difference in shear strength depending on the orientation of the split. Would you volunteer to shear test one with the split aligned horizonatlly, and another aligned vertically? Not having any empirical data, many of us have placed them with the split on the horizontal, in a slightly oval-entrance hole. Let's see if that's really a good strategy.
Thanks again for your testing work.
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bvb
Social climber
flagstaff arizona
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Nov 23, 2010 - 11:58pm PT
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dude. just solo it.
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Juan Maderita
Trad climber
San Diego, CA
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Nov 24, 2010 - 12:07am PT
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Hey BVB!
How are you? The runouts we did on those short 1/4" bolts down in Baja sure felt like solos!
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BeeHay
Trad climber
San Diego CA
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Nov 24, 2010 - 12:15am PT
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Hey, whatever, this is cool stuff. Thanks for posting.
And, you woke up BVB!
BH
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BeeHay
Trad climber
San Diego CA
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Nov 24, 2010 - 12:17am PT
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BVB only did "walkouts". Dude is way too messed up to run.
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bhilden
Trad climber
Mountain View, CA
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Nov 24, 2010 - 03:13am PT
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My guess why the coil bolt didn't go all the way in is that the coil worked itself far enough up the bolt before the bolt was totally screwed in to enlarge the working diameter of the bolt to be too large to go all the way into the hole.
If you look at the picture of the coil bolt after it has been pulled the coil appears to be all the way up the bolt. One nice things about the wedge bolt is that the sleeve doesn't start working its way down the cone until you tighten it.
Because you are screwing in the coil bolt you are already starting to tighten it. What if you pounded the coil bolt all the way in and then started unscrewing it (if the bolt head starts coming out that could be a problem).
When I think about the coil bolt, how it works and how it is installed it just seems like it is a bad design all the way around.
Bruce
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 25, 2010 - 01:36am PT
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Okay, finally got back to this and found my error.
After I broke the original digital readout (see my Nov 11, 2010 posts) popping the 1/4 SS wedge bolt, I dug out another digital readout and went down to the university and calibrated it so that I can use it with two load cells by changing the calibration scale numbers. All I have to do is remember to change the settings - which I didn't. So, in regard to the most recent tests, I calculated the correction factor based on the ratio of the two settings and got 2.96 (3-digit accuracy). I then set up the load cell in series with yet a third load cell, compared the two and got a factor of 3.0 (2 digit accuracy).
I am red faced to admit it but cockpit error occurred. The test gear works fine and the calibrations are good. Now I just wish I could edit the above posted results but don't see how to. Is it possible to edit old posts or even delete the thread and start over?
This does not change any of my results other than the last two, the 1/4 x 1-1/2 button head tests.
The 1/4 x 1-1/2 button head tension test should be 1860 lbs
The 1/4 x 1-1/2 button head shear test should be 3340 lbs
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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Nov 25, 2010 - 01:42am PT
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The 1/4 x 1-1/2 button head tension test should be 1860 lbs
The 1/4 x 1-1/2 button head shear test should be 3340 lbs
Totally BOMBER!
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Mungeclimber
Trad climber
sorry, just posting out loud.
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Nov 25, 2010 - 01:51am PT
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within expected parameters?
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bhilden
Trad climber
Mountain View, CA
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Nov 25, 2010 - 02:24am PT
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What has been pointed out before, the brand new test numbers are interesting, but what is more interesting is the degradation in the numbers over time.
20 years from now, what is the pullout and shear strength of the same bolts? Obviously, environmental factors play a big part in the equation, but I think that is the crux of the issue with respect to 1/4" bolts.
Bruce
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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Nov 25, 2010 - 01:41pm PT
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I've pulled enough old 1/4in bolts to know that 20 years from now they're pull out strengths are a crap shoot at best.
Some are solid as the day they went in, some pull out with your fingers and some snap with little effort. Couple that with the failure rate of the old style Leepers and you're playing Russian Roulette.
When I'm on the sharp end, I could care less about how solid the bolt will be in 20 years, cuz sometimes there won't be a "20 years" if I take too long. And if you think (not that you do, but some do) that you can drill a 3/8" x 2 1/4" bolt even nearly as fast as a 1/4" x 1 1/4" rivet. You my friend would be living in a world of delusions.
1/4 in rivets still serve their purpose, and I'd suspect they will continue to do so for many years to come.
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mucci
Trad climber
The pitch of Bagalaar above you
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Nov 26, 2010 - 12:13am PT
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Fully Bomber.
I have made a full conversion to 1"x 1/4" buttonheads for drilling on lead.
Even got a line on SS hangers for the split shafts...
It's the WAVE OF THE FUTURE!!!
Mucci
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cragnshag
Social climber
san joser
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Nov 26, 2010 - 12:16pm PT
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I like the challenge of placing 3/8" on lead. It requires me to find really good stances... but really I'm just lazy and I don't want to have to return with the tuning forks and drill again.
Of course most routes I climb are on the easier side, so good stances tend to show up when you need them. And I do carry a couple 1/4" buttonheads and a 1/4" bit in the bolt kit "just in case." Problem is I have to plan ahead and switch the bits at a good stance ahead of time since that would be very hard to do (with the Pika anyway) whilst clinging at crappy stance...
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 26, 2010 - 01:56pm PT
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Moses is making 1/4 hangers
http://mosesclimbing.com/lightweight-14-bolt-hanger/
I need to get some to test.
I don't really have a problem with 1/4 inch wedge bolts - particularly for backcountry - but I don't like the split shanks. The range of hole size that they will hold in is too small. Remember, for these tests I am drilling perfect holes in perfect rock.
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Juan Maderita
Trad climber
San Diego, CA
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Nov 26, 2010 - 02:16pm PT
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Banquo,
Not following your logic here. Wedge anchors are also dependent on having the proper size hole. Neither type of bolt should be used in anything but hard rock.
1/4" wedge anchors have a thinner coss section due to the threads.
Wedge anchors are not removable. The Powers "Drive" (aka: "split shank") is removable.
I'm not seeing a valid reason for ever using 1/4" wedge anchors.
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cragnshag
Social climber
san joser
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Nov 26, 2010 - 02:41pm PT
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JM,
Not just any 1/4" wedge anchor, but a 316 stainless steel wedge anchor.
Plenty strong (see tests upthread). The alternative light and quick-to-drill anchor is a carbon steel 1/4" buttonhead. Yes it is removable, but who is going to have a tuning fork in the true backcountry? It will get placed and be good for 20 years. Then it becomes a time bomb or simply junk.
This 316 SS 1/4" bolt is not meant to replace 3/8" in the backcountry, just 1/4" non-stainless alternatives where replacement is not likely.
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Juan Maderita
Trad climber
San Diego, CA
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Nov 26, 2010 - 03:58pm PT
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cragnshag,
You make a better case for placing 1/4" wedge anchors under specific circumstances. Perhaps it comes down to one's belief in "replacement is not likely" as a truth. First ascensionists in the backcountry will have to decide the ethical considerations of using a bolt which cannot be removed (except by the extreme method of core drilling with a power drill) for themselves.
What brand of 1/4" 316-SS wedge anchors was tested?
I see different torque specs of 4 and 8 ft-lbs. Let's hope that anyone placing these is quite cautious when torquing. That isn't much torque. It would be really easy to overtorque with one hand, creating a dangerous condition with a stretched and weakened bolt. Many people are unaware that torque specs for stainless are significantly lower than for carbon steel.
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cragnshag
Social climber
san joser
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Nov 27, 2010 - 02:22pm PT
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The tested 316 SS 1/4" are made in Canada by Simpson.
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Slabby D
Trad climber
B'ham WA
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Nov 27, 2010 - 04:49pm PT
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Recently climbed a wall in the Great White North where the first half had been bolted with 1/4" buttonheads and the second half with 1/4" stainless kb3 wedgebolts. The buttonheads were terrifying; heavily rusted, the holes often cratered. The kb3s looked they could have been placed yesterday. Replace-ability is nice and all but there is certainly something to be said for longevity as well. If buttonheads can last 20 years I imagine a stainless wedgebolt can last a Lot longer. 50 years ago I doubt people imagined there would be 36v lithium ion drills that weigh 6 pounds and can drill a big hole in 20 seconds. Lord knows what technology will exist 50 years from now, but I'd bet bolt replacement is going to get a lot easier. From now on I'm going with the 1/4" wedge bolts.
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 28, 2010 - 08:03pm PT
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I did another test today because I fear we might be comparing apples to oranges. I sheared a 1/4" x 1-3/4” 316 SS wedge bolt with the same fixture I used for the 1/4 x 1-1/2 button head. I did this because the button head was tested with thick piece of angle (0.200") that I had switched to because the tests kept destroying the loading piece. If you look at the last button head test you can see that the shank near the head deformed in double curvature or an "S" shape because the thicker loading piece kept the head from rotating
This was not the case for the earlier 14" SS bolt where the nut rotated a bit.
Here is the latest test
Score so far:
1/4 x 1-3/4 316 SS wedge bolt
3460 pounds tension
3000 pounds shear
1/4 x 1-1/2 button head
1860 pounds tension
3340 pounds shear
I think as a back country anchor, I would pick the wedge bolt since it will last nearly forever. The fact that it cannot be removed might be a benefit or a deficit depending on how you look at it. I feel that the button heads are too susceptible to degradation due to corrosion or mechanical damage to either the steel or the rock. If the wedgie gets loose, it will simply tighten up again. If the button head gets loose, it is useless. Once a split shank is compressed, it is permanently deformed it cannot expand. The wedge bolt expands whereas the split shank contracts which is why the wedge bolt is so much better in tension.
Could the opposite of expand be despand or dispand?
Also, I hand drilled the hole for the SS bolt with a standard 1/4" carbide bit. After I drilled the hole I slid the 17/64" HSS drill into the hole and it fit fine. I think the two holes were about the same diameter.
Also, I triple checked calibration by comparing (hydraulic pressure) x (specified cylinder area) to measured load getting less than 1% difference.
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mucci
Trad climber
The pitch of Bagalaar above you
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Nov 28, 2010 - 08:35pm PT
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"Once a split shank is compressed, it is permanently deformed it cannot expand"
Once a split shaft is compressed it is in "Tension Mode". That design (split shaft) is meant to increase tension. The steel has memory that does not dissapear as soon as it is placed, rather the tension is in working mode until a change in the placement medium (weathering, water, high work load etc)
I find it very hard for one to lobby for a nonremoveable bolt in the backcountry. A simple button head for the FA, and a responsible future party with a tuning fork and drill can maintain a sustainable hole count.
The routes that these wedge bolts are in contention for are rarely done and should be treated as so during a subsequent ascent.
If I don't like a bolt's condition during an ascent, I have the right to replace using the existing hole.
Not a big deal with modern routes, but I have and will continue to bring a drill and do upgrades on any routes where my safety is comprimised by the condition of a bolt.
How many are in the same boat?
Thanks for the testing BAnQ, lots of good info here.
Mucci
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Banquo
Trad climber
Morgan Hill, CA (Mo' Hill)
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Topic Author's Reply - Nov 28, 2010 - 09:49pm PT
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Mucci, how ya been?
Perhaps you can explain what you mean by "Tension Mode" but here's what I see. When I pulled the button head out, it was permanently compressed and looked like this:
Measuring it is a bit crude but it looks like it would just about fit into a 0.28" hole barely touching the sides after being compressed in the tension test hole. (the straight shank part is about 0.24")
When I measure hand drilled 1/4" holes, they come out closer to 0.26" - 0.27" so the split shank might be expected to have 2/100ths of an inch of bite but probably less since it actually enlarges the hole when it goes in. If asked under oath, I would say my best estimate is that a newly placed button head has about 1/100th inch of elastic compression or bite - not much to hang your life on. Over time, that can only decrease due to weather and corrosion. Also, mechanical damage due to rock fall or ice fall knocking on the hanger might loosen it. Any wiggle such as clipping it and hanging on it can only weaken it. Pretty much anything will reduce the strength while only replacing it can increase the strength.
So, yes, very good for first ascent but I think questionable for second. On the other hand, the 316 SS bolt is probably good, with basically unchanged strength, for many, many years.
According to the last page of this paper:
http://www.safeclimbing.org/education/Heavy_Climbers_Beware.pdf
A 300 lb climber has to take a 4.8m, factor 1.7 fall to generate 13.3 kN (3000 lb) impact. If there is any chance that an anchor will be exposed to anything like that, I would place a 3/8" bolt anyway. I wouldn't place a 1/4" anything on a route I thought might get a lot of traffic.
Anyway, the very few bolts I've ever placed were 3/8"
Just my opinions, I hope others have their opinions and will explain them to us.
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mucci
Trad climber
The pitch of Bagalaar above you
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Nov 28, 2010 - 10:12pm PT
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1800+ lbs of pullout with 1/100th of an inch tension?
Sounds pretty good to me.
Tension Mode would be the "in situ" split shaft. Maybe the wrong term?
The metal is tensioned due to memory, why else would there be a split?
Of course I am not a machinist and actually know very little about metal. It just seems as though the design trait of the split shaft is tension.
Why is the pullout so high if the tension is so low?
Thanks for info Banq, it has been very interesting to see your work on all of these bolts!
Mucci
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Fritz
Trad climber
Choss Creek, ID
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Nov 28, 2010 - 10:13pm PT
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Banquo: It is great that you are willing to put so much work & expense into doing this testing.
I haven't placed a 1/4" buttonhead on lead since about 1979, but it very good to see all this wonderful information.
It gives me more, or sometimes less, confidence in some of the old stuff the old me finds on lead in Idaho.
Thank you! Fritz
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Thorgon
Big Wall climber
Sedro Woolley, WA
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Nov 28, 2010 - 11:38pm PT
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Banquo,
What Fritz said, thanks for your tireless efforts!
Thor
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speelyei
Trad climber
Mohave County Arizona
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Jan 15, 2014 - 09:33pm PT
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BBST
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Steve Grossman
Trad climber
Seattle, WA
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Jan 15, 2014 - 11:45pm PT
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Greg- You guys have pulled thousands of 1/4" split shaft Rawlbolts.
How many of them have a corroded break at the top of split especially the ones that come out easily?
I walked away from 3/8" X 2 1/2" split shafts when I cleaned one off of El Cap with two blows exposing an 80% corroded face on both sides of the split.
I have placed hundreds of them on lead thinking I was doing the right thing for the long haul. If one of my bolts fails on you it won't be pretty since I tend to spread them out.
Tortured metal makes for poor anchors in the LONG RUN so if you are going to drill and not come back then don't use mild steel split shafts.
Initially they are good and reasonably strong but they don't stay that way.
Ed Leeper wrote an article confirming the unreliable nature of split shaft bolts including the 3/8" variety that I came across in my research too late to heed his advice and switch to stainless 5 piece anchors.
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Greg Barnes
climber
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Jan 16, 2014 - 02:02am PT
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Steve, I don't see that many snapped buttonheads - once you use tuning forks instead of prying, they tend not to snap. But it depends on the climate - for instance Tuolumne buttonheads nearly always pull easily (freeze-thaw) while rusted Valley buttonheads are more likely to snap. The more rusting, the more likely to break.
When they do snap, seems like it's typically at the top of the split. I've seen it higher up (base of the hanger) as well, and every once in a while halfway down the split.
I think 3/8" buttonheads tended to require more "sledge-hammering" to place in hard rock, and so might be more likely to have damage incurred during placement. I haven't pulled many of those (especially if you don't count softer rock areas where those 3/8" buttonheads were not compressed - Pinnacles, Red Rocks, Joshua Tree), but they often just seemed smashed up. I hope that your experience with them failing easily is not representative of most of them, because a fair number of those bolts are out there, from local cragging like Castle Rock State Park to multipitch areas like the Needles (I think Greg Vernon used those for replacement, sometimes with those Altus titanium hangers).
Do you have a copy or a link to Ed Leeper's article on buttonheads?
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Roger Brown
climber
Oceano, California
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Jan 16, 2014 - 07:45am PT
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Steve,
I agree with Greg. We have gotten better at pulling them. Even if cracked. we are getting better at getting them out in one piece. I have a feeling that the cracked ones were damaged during placement. I have almost every bolt that I ever pulled so maybe when I get old I will do a little research. I believe everything goes back to the hole. Power drilled hole in super hard rock may have a lot to do with it. I have been pulling a lot of 5/16 lately and have yet to find a cracked one, but that is a whole different mystery.
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Steve Grossman
Trad climber
Seattle, WA
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Jan 16, 2014 - 11:30am PT
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Greg and Roger,
Thanks for the response. I will try and find the Ed Leeper article to post but it may take a little time as I didn't scan it initially.
I would hate to see folks going back to this kind of anchor based on the testing and discussion here. The 3/8" split shaft Rawls that I used and the one that turned me away from this type of anchor are the threaded variety. A couple of rebolting accounts have mentioned shearing while trying to refit 3/8" studs with new hangers since you didn't have the means available to pull them out. I suspect that the portion remaining in the hole likely showed considerable corrosion.
I have used 1/4" button and bevel headed split shaft bolts on walls in aid applications. I have also had problems with the tempering on one batch of button heads that made them buckle on the way in. I stopped placing skinny bolts on free climbs very early on in my climbing career.
Take a look at the top of the split for a stress fracture line if you want to examine some of your pulled bolts with a magnifying glass.
Is the ASCA even considering using these? I hope not.
Cheers,
Steve Grossman
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Greg Barnes
climber
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Jan 16, 2014 - 11:56am PT
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Hi Steve,
No we are DEFINITELY not suggesting or using 3/8" split shafts! Besides we only use stainless steel bolts (except rare cases with big bolts in soft desert sandstone) and 3/8" split shafts are not made in stainless.
We do still supply the 1/4" split shafts for (no hanger) rivet replacement on aid routes. We encourage using Bryan Law's two washer idea for those, that way the second washer will help prevent rock damage when the 1/4" is replaced in the future.
Even if the bolts were always super strong, it's very hard to remove bigger split shafts without damaging the rock.
Greg
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Steve Grossman
Trad climber
Seattle, WA
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Jan 16, 2014 - 12:16pm PT
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Greg- A suggestion if you are trying to extract 3/8" split shaft studs.
Get a cordless die grinder set up with a thin cutting disk so that you are able to cut through one side of the split once you have eased the stud out to the point that this is possible. Most 3/8" studs have been placed such that the split point isn't very far below the rock surface. If the whole show fails after your cut then you can use a punch and push the remainder back in and patch the hole.
I have loads of these to replace. Sigh...
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jonnywoodward
climber
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Jan 17, 2014 - 01:46am PT
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Anyone clipping one of those old 1/4 inch split shaft bolts (they were called Rawl Drive bolts) should be very, very scared if it is providing essential protection.
After removing probably in the region of 800 of these I can attest that one has no idea what one is clipped into. While some of them are a bugger to get out, and would hold Arnold on a full pitch whip, some of them come out after a few light taps of the hammer on the pin, and at Josh a number of them were pulled out by hand with no tools at all. Your two year old daughter could get some of these things out. Additionally about 1 in 8 come out of the hole with a rusted fracture on one end of the shear (split), evidence that the structural integrity of the bolt was substantially compromised at some point during its life in the hole. The fractures seem to be divided pretty evenly between the two locations, and usually mark a bolt which was easy to pull out. Almost all the bolts I have exprience with date from the 70s and early 80s, and were removed over the last 10 years. If you are still placing these bolts, you are placing time bombs with the clock set to random. Whether that's OK or not is a matter of opinion.
In case you were wondering, about 780 of those 800 were actually replaced.
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Mungeclimber
Trad climber
Nothing creative to say
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Jan 17, 2014 - 03:20am PT
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In case you were wondering, about 780 of those 800 were actually replaced.
That's a lot of replacing. Thx!
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Steve Grossman
Trad climber
Seattle, WA
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Jan 17, 2014 - 10:52am PT
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At last, a light in the forest.
Thanks JW!
I get really tired of repeating myself on this issue.
Good on you for your extensive replacement work.
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bhilden
Trad climber
Mountain View, CA/Boulder, CO
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Jan 17, 2014 - 02:04pm PT
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I have seen the same thing as Jonny with respect to broken shafts of 1/4" split shaft bolts.
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henny
Social climber
The Past
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Jan 17, 2014 - 05:33pm PT
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The worst case of breakage that I've seen on a 1/4" split shaft was the bolt at the top of the dihedral on the second pitch of the Iron Cross at Suicide. A single light tap to start driving a pin under the hanger popped the bolt out. It had completely broken through both splits of the shaft, leaving all of the bolt from the start of the shaft split onwards in the hole. The rust and corrosive build up completely covered the broken end of the bolt, indicating that it had not "finished" breaking due to removal.
The bolt visually looked fine, but what a surprise lurked inside the hole.
Like Woodward said, you never know what you're getting with old 1/4" bolts. It isn't all that uncommon to see cases where half the shaft is broken when removing them.
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Steve Grossman
Trad climber
Seattle, WA
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Jan 17, 2014 - 07:40pm PT
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Once I locate the Ed Leeper article I will start a thread so that folks stop placing these bolts as permanent anchors when they suck for the long haul.
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