Retiring carabiners after being dropped?

[treehumper]

A buddy sent me this link about the topic from fat canyoner.

http://fatcanyoners.org/bush-guide/dropped-carabiners/

Interesting study.

What's your take?

 

[Tom Dunlap]

Send all dropped biners to me for further testing.

 

[jomoco]

I have retired quite a few aluminum biners after observing what using them to speedline light brush down does to them.

http://www.youtube.com/watch?v=oFjqN00R2Ho

Not that I destroyed them or anything. They're still handy for hanging helmets and other light equipment on in my truck.

jomoco

 

[Viking]

There is a video out there of ISC dropping, then breaking beaners. The exhaustive number of drops did not change break strength at all.

 

[wyoclimber]

Black Diamond tested a bunch of gear a few years ago. The batches were of all different ages and they were dropped from different heights (some off of El Cap, 3000 feet). They all tested just fine unless there was visible damage. A speedline would do just that damage needed to reduce their strength. Same reason fixed draws at climbing areas are so scary.

 

[wyoclimber]

A bunch of MIT students did some tests as well and determined that microfractures were a myth. They x-rayed and broke a bunch of carabiners and quickdraws. What they did find was that once an aluminum carabiner had been loaded beyond its rated capacity it could break unexpectedly. So if you have reason to believe that carabiner had been subjected to forces in excess of 22kn (for the average aluminum biner along its major axis), retire it.

 

[Norm_Hall]

[ QUOTE ]
A bunch of MIT students did some tests as well and determined that microfractures were a myth. They x-rayed and broke a bunch of carabiners and quickdraws. What they did find was that once an aluminum carabiner had been loaded beyond its rated capacity it could break unexpectedly. So if you have reason to believe that carabiner had been subjected to forces in excess of 22kn (for the average aluminum biner along its major axis), retire it.

[/ QUOTE ]

Cycles to failure.
This would hold true with any piece of arborist equipment, hardware or software.

 

[wyoclimber]

Here is a link to the MIT study.
http://web.mit.edu/sp255/www/reference_vault/Fatigue_Presentation.pdf

 

[knudeNoggin]

[ QUOTE ]
... So if you have reason to believe that carabiner had been subjected to forces in excess of 22kn (for the average aluminum biner along its major axis), retire it.

[/ QUOTE ]

Or, maybe more likely, if the 'biner had been
>>> loaded abnormally (not along major axis,
perhaps clipped into something so large as
to shift load away from that --e.g., rope
so thick it had to be reeved through!?).

(That one reference to two fellows presenting testing data
to ITRS that showed no loss of strength and yet recommending
retirement really spells out their vested interest!)


*kN*