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Rockalanche
Jul 27, 2013, 1:11 AM
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Registered: Mar 25, 2012
Posts: 21
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Couple of weeks ago I got myself into a pretty bad climbing incident. I ended up dropping some carabineers atleast 150 feet that smashed off the rocks below. I retired them for that reason. So this begs the question What is your thought on micro cracks? real? fake? what ?
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5.samadhi
Jul 27, 2013, 2:36 AM
Post #2 of 6
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Registered: Jul 31, 2011
Posts: 98
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If they weren't visibly smashed or broken I would probably still use them. Maybe thats real bad though I have some pretty beat up gear in the various sports I engage in and I havent died yet.
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curt
Jul 27, 2013, 4:37 AM
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Registered: Aug 27, 2002
Posts: 18275
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Rockalanche wrote: Couple of weeks ago I got myself into a pretty bad climbing incident. I ended up dropping some carabineers atleast 150 feet that smashed off the rocks below. I retired them for that reason. So this begs the question What is your thought on micro cracks? real? fake? what ?
Go find us a micro crack and report back. Hint: they often hang out with Elvis and the Loch Ness Monster.
Curt
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acorneau
Jul 27, 2013, 1:56 PM
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Registered: Feb 6, 2008
Posts: 2889
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From OnRope's page...
"Myth #1: You should replace a dropped carabiner because of undetectable "Micro-Fractures".
This is the biggest myth we know of, and was probably created by unscrupulous salesmen to get you to buy more carabiners.
Truth: In a test by Steve Nagode, an engineer at the REI quality assurance laboratory, 30 carabiner bodies (half ovals, half D’s) were each dropped six times onto a concrete floor from a height of 33 feet. Following the drops, their open-gate strength was measured and compared to 30 control samples from the same production batch and which had not been dropped. The statistical result showed "no loss of strength.” Inspect any piece of dropped equipment carefully, checking for proper function. Cast metal products are most vulnerable to damage, fractures and cracks. To my personal knowledge, this happened once to a gray cast metal Jumar ascender in the 1970's. To my extensive knowledge: Drop forged carabiners (and similar gear) have not exhibited this problem.
Note: OEM Petzl says: 1mm of wear or gouge is serious enough wear or damage to require replacement."
Lots of other myths addressed here...
http://onrope1.com/mythbusters.htm
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marc801
Jul 27, 2013, 9:25 PM
Post #5 of 6
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Registered: Aug 1, 2005
Posts: 2806
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Rockalanche wrote: Couple of weeks ago I got myself into a pretty bad climbing incident. I ended up dropping some carabineers atleast 150 feet that smashed off the rocks below. I retired them for that reason. So this begs the question What is your thought on micro cracks? real? fake? what ?
http://www.rockclimbing.com/...p;sb=score&mh=25
...gives you 681 posts with "microfractures". You can do your own search for "microcracks", "micro cracks", "micro fractures", or any other variants you dream up.
Happy reading.
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knudenoggin
Aug 23, 2013, 10:02 PM
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Registered: May 6, 2004
Posts: 596
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And some of that there "here" is ridiculous --amazed that it got published
(and REMAINS so)!!
--to wit:
In reply to: These three are allotted for when using the 10 to 1 safety margin. Unless any of the three are excessive, i.e. a 20 year old wet rope with an overhand knot (50-55% efficiency) can push a rope beyond its life support abilities. ( -40% age, - 15% wet, -45% knot) = 0 strength.
By similar mis-reasoning, if you tied several knots in a rope
you could weaken it also to "0 strength" !!
*kN*
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