Southern Yosemite Climbing Discussions
Southern Yosemite Categories => General Discussion => Topic started by: daniel banquo merrick on November 12, 2015, 09:36:11 pm
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I don't know if any of the SoYo climbers are using 1/4" hangers and anchors but I have been thinking about them and thought I'd share a few thoughts. I think 1/4" anchors have their place as temporary placements on first ascent and as permanent placements on back country climbs that won't see much traffic. A list of a few things:
1) The UIAA requires anchors (hanger and bolt) to withstand 25 kN in shear and 15 kN pull-out without failing. That's 5620 lbs and 3370 lbs for aMerrickans. The UIAA requirement is based on worst case factor 2 fall and rigid belay.
2) The UIAA minimum for cams is 5 kN without damage. 1120 lbs
3) The UIAA minimum for chocks is 2 kN without damage. 450 lbs
4) Measured anchor forces by Petzl with belay device:
Fall Factor Anchor Force
0.3 4 kN
0.7 5 kN
1.0 6 kN
5) I made some hangers out of 1x1x1/8 304 SS. Materials cheap but fabrication takes time.
6) I bought a box of 100 Simpson "Strong-bolt 2" 1/4" 316 SS bolts. Box of 100 cost roughly $100.
7) #5 and #6 above tested together results:
Pull out (hanger prying on bolt) 2130 lbs ( 9.5 kN)
Shear 2760 lbs (12.3 kN)
8) In both tests the bolt failed and the hanger suffered minimal damage. Note that the forum sees my eight followed by parentheses as a cool-guy emoticon.
9) Camalots:
Strength :
[0.3] 8 kN, 1798 lbf
[0.4] 10 kN, 2248 lbf
[0.5] 12 kN, 2698 lbf
[0.75-6] 14 kN, 3147 lbf
10) Stoppers:
Strength :
[size 1-2] 2 kN (450 lbf)
[size 3] 5 kN (1124 lbf)
[size 4-5] 6 kN (1349 lbf)
[size 6-12] 10 kN (2248 lbf)
11) My conclusion is that a 1/4" anchor of good quality is better protection than a small cam or any chock.
I think proper 1/4" anchors are OK as permanent protection but the route description should describe the bolts and climbers should trust them about like they should trust a stopper. 1/4" anchors would never be acceptable on anything even close to a sport climb.
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11) My conclusion is that a 1/4" anchor of good quality is better protection than a small cam or any chock.
I think proper 1/4" anchors are OK as permanent protection but the route description should describe the bolts and climbers should trust them about like they should trust a stopper. 1/4" anchors would never be acceptable on anything even close to a sport climb.
I doubt you'll get much disagreement from this crew. However, the chocks rated down to 450lbs are scoped for use in a different primary usage. Chocks of that kind, aren't designed as permanent installations. They are 'bail' gear as a last ditch option, or are used in aid climbing, or used nominally in free climbing. As such we should be detailed in equivocating between small cams chocks and quarter inchers.
1/4" anchors are stronger than most think they are, but their use must be prescribed by 1)type of rock 2) expected life span and 3) should not be a SPOF placement if using quarter inchers. In other words, if the only gear is bolts in a long pitch, I don't think it should be a recommended practice or even an 'accepted practice' to do quarters for long term 'leave in place'. And last, quarters shouldn't be placed by someone new to the game. Even the slightest margin of error and you reduce that quality hole you pull tested on into a flaring and downward facing hole that bottoms out the bolt.
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Jeez, I didn't know the Stopper and Camalot ratings were that low!
Hmm, temp replacement of 1/4" carbon steel with 1/4" SS? Interesting suggestion. I think there is a 1/4" hardware=death reaction from most folks these days. In the event of updating 1/4 for 1/4 you would still have to drill deeper for the new 2-1/4" since most buttonheads are 1" or 1-1/2". One might say "you might as well drill 3/8in if you need to redrill at all" but the weight difference of a 3/8" hand drilling rig (bolts+hangers+drill bit) is drastically heavier and way less attractive in the backcountry.
I don't understand the mixed materials corrosion issue (stainless and carbon steel combo), so the stainless 1/4" studs sound pretty appealing with those ratings. I used a lot of carbon steel buttonheads with SS hangers in the past and know that corrosion of the bolt will be the issue in the long run. In my old 1/4" replacement experience, old buttonheads have been overall pretty solid with a handful of exceptions. The exceptions do haunt me...
8) hey the number eight next to a parenthesis does make a smiley!!
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you would still have to drill deeper for the new 2-1/4"
The Simpson "Strong-bolt 2" 1/4" 316 SS that I bought only require 1-1/8" embedment which is how I tested them. You could pop out an old split-shank and simply install a 1/4" bolt. No drill required and with a new SS hanger you have an anchor that should last a generation or two.
mixed materials corrosion issue (stainless and carbon steel combo)
The combination of the two roughly means that the carbon steel does all the corrosion for both parts. A not entirely accurate way to picture what happens but close. A CS bolt with a SS hanger will cause the CS bolt to corrode faster than it would with a CS hanger. Not only does the bolt corrode faster but most of it is hidden and the hanger looks great because the CS is protecting it from corrosion.
Another thing to watch for is stress corrosion cracking (SCC) which occurs when there are residual stresses in the SS. Bending SS leaves residual stresses and promotes corrosion. This is one reason I've been making hangers out of angle. If you do bend, use the largest radius you can. SCC and corrosion of SS probably isn't a big concern in most of the Sierra so SCC isn't a big concern to most of us.
One thing to consider is placement in acidic environments. Granite is basically inert so any acids that develop from decaying plant matter or acidic rain will remain. Place anchors where they will stay dry away from any seeps.
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Let's go replace some hardware. 8) Yup for the end closer parent.
This combo only makes a sad face: 8(
Thanks for all the info Dan, what a resource!
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The Simpson "Strong-bolt 2" 1/4" 316 SS that I bought only require 1-1/8" embedment which is how I tested them. You could pop out an old split-shank and simply install a 1/4" bolt. No drill required and with a new SS hanger you have an anchor that should last a generation or two.
Wouldn't that leave about an inch sticking out?
Bolts of any diameter that stick out past the nut can break a biner if they get lodged in an unfortunate way and loaded on a fall. A 1/4" stud would probably bend but 3/8 will surely break a biner in half.
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They are only 1-3/4" long. The hanger is 1/8 plus 1/4 for the washer and nut. That does leave 3/8" plus a bit after tightening. My hangers are so small a biner can't snag on the stub but it would be better to have a deeper hole.
(http://danielmerrick.com/SOYO_photos/0.25-1.75.jpg)
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Well there you go, 1-3/4" is much better than 2+".
I was thinking that the suggestion of replacing old 1/4" carbon steel with 1/4" stainless sounds much more attractive to those who want to update hardware but are turned off to the difficulty of upgrading to 3/8". In the backcountry you don't al have the time to spare.
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Sometimes I think we are fundamentally changing the character of old climbs by replacing 1/4" anchors with larger. Certainly old rusty split shanks and Leeper hangers should be replaced but I think replacing 1/4" with 1/4" should be considered - especially if the expected fall factor is 1 or less.
Sort of a historic preservation thing.
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Except that a quarter was the adequate protection of the day. Replacing with 3/8 is just replacing with protection of the day, with the benefit of hindsight of how quarters can fail.
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I suppose the biggest flaw with the hardware of the day was that the carbon steel split shafts don't hold up over long periods of time and that is ultimately a materials problem. That and the Leeper recall probably made climbers rethink our hardware standards. If they had used 1/4" wedge bolts as the standard, we (at least I) would perhaps be a little less freaked out about 1/4" hardware. Also, some people don't realize that 1/4" hangers were sold regularly well into the 90's which would make some hanger/bolts only 20 years old. The last SMC stainless hangers were pretty thick and high quality but most of them are pinned to routes with rusting carbon steel bolts.
A separate common hardware of the day ( like as far back as the 40's) were those Star-dryvin pieces of crap and they were often 5/16" or 3/8" so they can't say they weren't willing or able to drill that size of hole back then!
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Well said.
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I think the climbing community has been irrational about embracing the UIAA standards for all situations. Yes, 25 kN is a good idea sometimes but for most placements it is simply overkill. If a sport climbing bolt is going to take 100's, if not 1000's of falls, 25 kN is a fine idea. A bolt on a remote moderate slab is simply never going to see anything like 25 kN. There is a discussion going on over at MP which has brought up government funded replacement of climbing anchors in Europe. That's just what we need, the rangers overseeing permanent anchors.
Right now the biggest obstacle to putting up new routes with 1/4 anchors is the lack of commercial hangers.
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Dan,
I am intrigued with your comment about retaining the feel of a climb by keeping the 1/4" hardware. I can relate to that when, for example, 30 years of climbers clipped old bolts and therefore had a shared experience but how else?
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Climbing a route with 1/4" anchors requires a different commitment. There is a thread going on ST where somebody complains that the bolts found on JT climbs are too scary. The old climbers tell him to suck it up and grow some balls or climb something else. Same idea.
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Eventually enough modern climbers with 3/8" as the standard will replace belay "anchors" for sure.
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I think the FA party had the least scary experience with the 1/4" hardware since it was new and they may know the quality of the rock and hole and act accordingly. Everyone from then on would have a progressively scarier experience. Eventually there would be a point that a party could be putting their well being on the line more than the FA!
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I have a box of wej-it 1/4" x 1-3/8" sleeve anchors. If anybody is doing temporary 1/4" bolting you might consider these since they are easy to remove. Simply tighten with a wrench until it breaks, tap in the stud, pull out the sleeve and then the stud. I've tried it and it works well. Much easier to get out than split shanks. You do need some sort of punch, needle nosed pliers and maybe tweezers.
I have about 75 of these in 304 SS if anybody wants some to try. Cost me about $0.50 each. I also have about 75 of the Simpson 1/4" x 1-3/4" wedge anchor in 316 SS if any body wants some which cost me about $1 each.
(http://danielmerrick.com/SOYO_photos/0.25%20sleeve.jpg)
(http://danielmerrick.com/SOYO_photos/0.25%20anchors.jpg)
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Banquo, have you done any 1/4” work yet? I saw this after Looking into 1/4” split shanks. I found stainless but could only order them in like 10,000 lots. 1/4” seems great for hand drilling in back country.
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Nope, I haven't placed a bolt in two years. Haven't climbed either.
I've been developing and making hand-powered tools for bolt removal. Especially for removing wedge bolts. We can usually remove 3/8" wedge bolts. Sometimes we fail when the threads are gone or some idiot set them in adhesive. I think I've figured out how the get the adhesive ones out but need to do some more testing.
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Yikes! Why on earth would they use adhesive with a wedge anchor? Trying to avoid rust?
I have not replaced any bolts except ones that were so rotten they were falling out. Any good tutorials you would suggest?
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A big issue with removing bolts is how many types of bolts there are. Each type requires a different method and often different tools. Fun problem solving really. I've made tools specifically designed for one particular bolt.
1/4" split shanks are usually removed by driving wedges under them. Wedges are usually made by cutting a slot in a lost arrow so it looks like a tuning fork.
To get a wedge bolt out, loosen the bolt by taking off the nut and tapping it in with a hammer. Then you spin the bolt, usually with some abrasive grit, until the sleeve wears a groove in the expansion cone. Then you pull it out. The groove in the cone lifts the sleeve out and prevents it from expanding on the cone. People use a power drill to spin the bolt but in Yosemite, Pinnacles and in a wilderness, we use a modified speed wrench.
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the hard part is not damaging the heck out of the rock with tuning forks and the hammer.
Dan, I think you or Bruce had vids of the modern technique, yes?
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This shows the tools. A spinning crank and a ball thread puller. The puller can easily generate 6000 lbs force.
https://youtu.be/2gUf5FMefvw (https://youtu.be/2gUf5FMefvw)
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Are you taking all that gear on the wall? That last tool is very specific it appears. Interesting
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We usually use this stuff on rappel.
Many different tolls have been made and tried; all thread pullers, acme thread pullers, hydraulic pullers and finally the ball screw pullers. All thread or standard machine threads with a flat washer are about 8% efficient at converting the input work into tension. A ball screw with a roller thrust bearing is about 85% efficient. They are really pretty amazing.
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Poking around after using Mark’s old 1/4” hand drill. So much quicker. Found these stainless 1/4” and 3/8” button heads. They are the same concept of the split shank but more of a bent shank. Any thoughts?
https://www.mscdirect.com/product/details/68010685
https://www.mscdirect.com/product/details/68010883
It seems to me that the sheer strength on one of these SS button heads would be greater than a wedge anchor in the perspective size due to the increased amount of metal present at the hole entrance. It would seem that putting in threads for a wedge type bolt would be removing metal from the shaft that would weaken the sheer strength. For everything except the steepest and overhanging Stuff I would want more sheer strength. The back country weight factor is also very appealing. What do you think?
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Which type of hand drill is it? Rawl? 5.10? Photo?
Those bent-shaft bolts are probably only strong enough in 3/8" but you can't really pound them in with a typical climbing hammer. They require a mini-sledgehammer to pound in, especially the 3/8". Also, they are really easy to accidentally bend with a bad strike to the point they may permanently bind in their hole and never go all of the way in. Not a good idea for the backcountry. They are however SS and I don't believe you will find a split shaft in SS at all. The SS ones that McMaster Carr sells says the 1/4" has a pull strength of only 210lbs!
Split shafts are pretty bomber, time is their weakness. They simply lose their "spring" that keeps them in the hole when they get too rusty which can be years or decades. That and and sloppy drilling.
Don't get 1/4" hole wedgies, the shaft is actually 3/16" (#10 screw) which is good for hanging a picture of grandma but not enough meat to fall on with any confidence. Really freak out when you see them out in the wild, they are the most common to snap when pulling out with a tuning fork.
I have many homemade SS hangers for 1/4" if you need any. What you do is tap a split-shaft buttonhead into the hole and they stay in there until they are ready to pound in the hole so they are an awesome and light backcountry rig.
If in your research you run into anyone, probably an aid type person, that mentions the word z-mac or zamac, slap them in the face, they are useless even for grandmas picture!
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Zmac!!!!
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Thwap!!!
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I am not sure the make. It uses press fit bits that you knock out with a small wedge. I took a pic and will email it to you John since I can never post pics from my phone.
Interesting about those bent shaft. I was hoping they went in as easy as the split shank. I did find some SS split shank online back when this post was originally posted but you could only order them in lots of like a thousand or more. If I ever get some I would hit you up for some of those SS 1/4” hangers.
If I am going to use non SS split shanks then I wouldn’t want SS hangers. Do you have a connect for non SS 1/4” hangers?
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Before using any new anchor types please do some testing. I can help and have load cells, hydraulic pullers, etc. Things do not always function as expected.
I suspect that stainless that steel split shanks do not exist and the stainless bent shanks are too weak in pull-out because the common stainless (304 or 316) are not hardenable. Maximum hardness for 316 is about Rockwell B90 which is below and off of the Rockwell C scale (Rockwell C <0).
They do work-harden a little bit but can not be heat treated to harden. Even if you do work harden them, they are very soft compared to the carbon steel split shanks and bent shanks.
There are stainless steels that can be as hard as carbon steel but they are expensive and difficult to harden - the kind of stuff that knives are made of. Making anchors out of this stuff would probably be pretty expensive. I have never met a home knife craftsman who makes knives out of stainless because the heat treating is challenging.
The only affordable stainless that is easy to heat harden that I know of is 17-4. This is what BD makes hammerheads out of. I have made some hammers with it but don't like the result because the material cannot be made hard enough. To harden it you bring it up to a certain temperature for a certain amount of time in a process known as precipitation hardening. Maximum hardness is about Rockwell C40. I like my hammers about Rockwell C50. Carbon steel button heads are probably something like C60.
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(http://www.southernyosemiteclimbing.com/SMF/photo_album_resized/IMG_4559_resized.jpg)
Here is Mark Haymonds well-used hand drill from DaveyTree
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Tks John.
Not sure how long Mark had this particular one but it has seen some pounding
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I gave all my old bolting stuff and nicopress tool for copper heading to Mucci. lars