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alpinejibber
Sep 1, 2004, 2:57 AM
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I was wondering if there was a way to tell if you need to retire you dropped biners. other than just retiring them after they have been dropped.
I just dropped a draw while climbing and i was wondering if i could take it into bd and have them look at it, or if that would just be a waste of my time
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tnchief
Sep 1, 2004, 3:06 AM
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If you value your life, retire the draw. It's not worth the risk.
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talons05
Sep 1, 2004, 3:08 AM
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I have heard of people x-raying large amounts of gear. Supposedly this can show microscopic cracks that have developed -- this may be an urban legend. Besides, that's a chunk of change compared to replacing a single draw. If you dropped it more than about 10 feet, I recommend making a quick trip online or to your local shop to grab a new draw. Of course, it also depends on what it landed on -- rock? dirt? sand? your partners head?
A.W.
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iclimblilrocks
Sep 1, 2004, 3:10 AM
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It depends, how far it fell, if it slid or directly fell onto rocks or dirt, What it fell on, and how old it was.... But I think that You might as well retire it 20$ or your life.. its your choice
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curt
Sep 1, 2004, 3:23 AM
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In reply to: I was wondering if there was a way to tell if you need to retire you dropped biners. other than just retiring them after they have been dropped. I just dropped a draw while climbing and i was wondering if i could take it into bd and have them look at it, or if that would just be a waste of my time
To continue to use this gear further would be quite foolish. What you need to do is to send all questionable gear such as this directly to me. I will then assume all responsibility for its proper disposal. You can PM me for my mailing address. :lol: :lol: :lol: :lol:
Curt
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alpnclmbr1
Sep 1, 2004, 3:27 AM
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If you cannot see obvious damage, they are more then likely fine.
One of the gear companies(BD?) dropped a bunch of gear off of El Capitan, (1000m) and the gear that still looked good, tested full strength.
The micro fracture idea is a confirmed false urban myth.
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tnchief
Sep 1, 2004, 3:29 AM
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I have dealt a bit with X-rays of metal objects. While they may show cracks that are not visible, they will not show weak spots in the metal caused by a deformity (bending). Once metal is bent, even slightly, it's resistance to further bending (or breaking) is significantly reduced.
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rocknut
Sep 1, 2004, 3:33 AM
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I dont know the specific data on biner fatigue and crack propagation but aluminium alloys in general are very resistant to crack growth from high impact stress (falls) That is why jets exclusively use aluminium alloys instead of steel. In theory, the metal will have a 'long life' of use without being unsafe. But I agree that it's not worth a few bucks to risk your life over. Nothing is fool-proof so its best just to play it safe and replace your gear regularly.
Chris
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curt
Sep 1, 2004, 3:37 AM
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In reply to: I dont know the specific data on biner fatigue and crack propagation but aluminium alloys in general are very resistant to crack growth from high impact stress (falls) That is why jets exclusively use aluminium alloys instead of steel. Chris
So, I don't suppose weight has anything to do with it?
Curt
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coldclimb
Sep 1, 2004, 3:37 AM
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In reply to: It depends, how far it fell, if it slid or directly fell onto rocks or dirt, What it fell on, and how old it was.... But I think that You might as well retire it 20$ or your life.. its your choice
No offense meant at all man, but do you have the experience to be saying things like that? Judging by your other posts, I would guess that your experience level is far from that point.
I myself don't judge that I have the experience to give people advice regarding safety of gear that has been abused. All I have is wild conjecture based on my own reasoning, which I will always try to differentiate from proven fact.
I don't believe in microfractures. :)
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socialist1
Sep 1, 2004, 3:41 AM
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Just to clarify- X-rays are indeed used to inspect micro cracks in materials. More specifically, in industry they are used to inspect critical welds.
So unless you know someone who has access to a specialized machine like this, RETIRE IT. Use the biners to rack gear or something.
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jt512
Sep 1, 2004, 3:47 AM
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In reply to: I was wondering if there was a way to tell if you need to retire you dropped biners.
Yes. By inspection. If there is no visible damage, other than superficial scratches, and the gate function is good, then the biner should be good to use. This topic has been discussed many times on rec.climbing by metallurgists and materials engineers, and they've said, to a one, that aluminum gear might bend, break, or show visible damage, but it won't develop invisible damage.
-Jay
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ptone
Sep 1, 2004, 3:53 AM
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Wow--I've been away for months but it feels like home, so familiar!
I remember the first time I asked this Q at the local. Someone told me to take a couple of web-o-lets and clip the draw between the bumper of my truck and a loaded dumpster...if I could drag the thing all the way around the block, it'd prove it was perfectly safe to climb on afterward...
I got stopped ($105.00 ticket) on the third side of the block, so I had to retire it. It's a neat system, about the same degree of luck and all, but friggin expensive!!!
peace,
-p
Oh, and PS to Curt:
Sorry bro--I'd have sent it to you, but I sold it to this guy at the gym to help pay the ticket...now don't grind on me to quickly--I did the responsible thing and warned him of it's history beforehand, from when I dropped it on the grass setting up my harness for a climb, to the suspension of my license for not paying the ticket--he said he didn't care, he was a boulderer mainly, just wanted it for a keychain so everyone would know he climbed.
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traddad
Sep 1, 2004, 4:01 AM
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In reply to: In reply to: I was wondering if there was a way to tell if you need to retire you dropped biners. other than just retiring them after they have been dropped. I just dropped a draw while climbing and i was wondering if i could take it into bd and have them look at it, or if that would just be a waste of my time To continue to use this gear further would be quite foolish. What you need to do is to send all questionable gear such as this directly to me. I will then assume all responsibility for its proper disposal. You can PM me for my mailing address. :lol: :lol: :lol: :lol: Curt
Curt is obviously joking, or at least, that is what the little smiley feces are indicating. I, however, am not joking. If you are in ANY doubt, you should send your gear to me. I will analyze your gear extensively and send back any gear that passes my year-long regime of rigorus testing. I also extend this service to anyone who is unsure of their new rope.
Why be unsure when you can be secure?
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jt512
Sep 1, 2004, 4:04 AM
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In reply to: Oh, and PS to Curt: Sorry bro--I'd have sent it to you, but I sold it to this guy at the gym to help pay the ticket---he said he didn't care, he was a boulderer mainly, just wanted it for a keychain so everyone would know he climbed.
Sadly, that's about all the use Curt would have for it, as well.
-Jay
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cgailey
Sep 1, 2004, 4:39 AM
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In reply to: I don't believe in microfractures. :)
You know it John ;)
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rocknut
Sep 1, 2004, 4:51 AM
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High impact tensions stresses in metals do cause microscopic cracking of the metal which will eventually cause failure. Every time you put a high enough stress on the biner you will increase the crack lengh. This is called fatigue failure. Biners have an abnormal shape so if cracks form they typicaly will start on the inside surface of a curve. The first signs of cracks would almost be impossible to detect...super fine lines you might be able to feel on inside curves of the biner.
Techniclly biner strength ratings range from 10 to 30 kN depending on the loaded axis. A 200 lb person would exert about 1kN on a short fall. So we're looking at on tenth of the safe load limit. Realisticly, you're not going to break a biner. The only concern I would have is continued high impact loading (multiple falls) Even with that, the something else will break before the biner does.
All that to say, you gotta make your own choice.
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talons05
Sep 1, 2004, 12:50 PM
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It can't be that easy to cause a weakening bend in a carabiner. How many times does a box of hardware get dropped in shipping? Or by some geek at the shop where you buy your gear. Or by your partners when you're not looking?
A.W.
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cantbuymefriends
Sep 1, 2004, 1:15 PM
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In reply to: High impact tensions stresses in metals do cause microscopic cracking of the metal which will eventually cause failure. Every time you put a high enough stress on the biner you will increase the crack lengh. This is called fatigue failure.
I thought that "fatigue failure" was when you had a very LOW tension, but repeated A LOT, like 100 000 times or so. I seriously doubt that any biner that any climber ever use is gonna see even 1000 loadings. So the chance of a fatigue failure on a biner is non-existent.
However I suppose it's possible to get a biner to break from crack propagation after a few HIGH tension impacts. But then it is just that, high tension failure. Fatigue has nothing to do with it.
(Is there anyone out there who can calculate/estimate the tension impact on a biner dropped from, let's say, 100 ft?)
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overzealous
Sep 1, 2004, 1:24 PM
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In reply to: High impact tensions stresses in metals do cause microscopic cracking of the metal which will eventually cause failure. Every time you put a high enough stress on the biner you will increase the crack lengh. This is called fatigue failure. Biners have an abnormal shape so if cracks form they typicaly will start on the inside surface of a curve. The first signs of cracks would almost be impossible to detect...super fine lines you might be able to feel on inside curves of the biner. Techniclly biner strength ratings range from 10 to 30 kN depending on the loaded axis. A 200 lb person would exert about 1kN on a short fall. So we're looking at on tenth of the safe load limit. Realisticly, you're not going to break a biner. The only concern I would have is continued high impact loading (multiple falls) Even with that, the something else will break before the biner does. All that to say, you gotta make your own choice.
Depends on the crystaline structure of the material. Steel does not have a homogenous structure, so despite haveing a greater tensile strength than alunimum it can develope microcracks.
Aluminum does not, when stressed it will deform, not crack. Any deformation sufficent to weaken the biner to dangerous levels should be visiable.
I am not an engineer, so anyone with actual knowledge (not hearsay) feel free to jump in and correct me.
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rockgoat
Sep 1, 2004, 2:15 PM
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Who actually X-rays their gear? It would be cheaper to just throw it out. If in doubt get rid of it.
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brianinslc
Sep 1, 2004, 2:27 PM
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In reply to: Just to clarify- X-rays are indeed used to inspect micro cracks in materials. More specifically, in industry they are used to inspect critical welds. So unless you know someone who has access to a specialized machine like this, RETIRE IT. Use the biners to rack gear or something.
Hmmm....I'd say, x-ray isn't typically used to "see" cracks in aluminum. Good for discerning high and low density inclusions...
Try liquid dye penetrant. Etc.
Aluminum will crack (remember the cracks in the biners around the pins near the end of the gate on the old Coonyard D's?). Sometimes these hairline cracks are real hard to see.
Anyhoo, I probably wouldn't use a biner that had been dropped from a great height...but...might consider it after real close, careful inspection for any damage. I'd say if you can't see any damage, after a close, careful inspection (maybe even use 3X mag), then the biner is "probably" fine.
Brian in SLC
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the_pirate
Sep 1, 2004, 2:35 PM
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Informative thread.
In reply to: I have heard....
In reply to: I don't know.....
In reply to: do you have the experience to be saying things like that? Judging by your other posts, I would guess that your experience level is far from that point.
In reply to: I thought that....
In reply to: I am not an engineer, so anyone with actual knowledge .....
and people are all worried about the beginners fourm.... :roll:
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wyattwyattwyatt
Sep 1, 2004, 2:39 PM
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granted i am not a metallurgist, but the idea that a biner that is dropped should be tossed away seems a little silly. has anyone ever heard of any instance where an accident has actually been caused by a biner breaking(properly used -- i dont mean where someone forgot to lock it or something like that) ?
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