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Topic Date User

Etiquette on dropped gear 9-Nov-2011 At 11:45:07 AM Sabu

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>"Conventional wisdom says that a carabiner that has been dropped must
>be retired, even when there are no signs of damage. Perhaps not.
>In a test conducted by REI, thirty carabiner bodies (half ovals, half
>Ds) were each dropped six times onto a concrete floor from a height of
>33 ft. (10 m). Following the drops, their open-gate strength was measured
>and compared to thirty control samples from the same production batch that
>had not been dropped. The statistical result was no loss of strength.
>According to Chris Harmston, the quality assurance manager at Black Diamond,
>“I have test-broken hundreds of used, abused, and dropped ‘biners (even
>some that fell 3000 ft. (1000 m) from the top of the Salathe Wall on El
>Capitan). Never have I noticed any problem with these unless there is obvious
>visual damage to the ‘biner. While somewhat reassuring, this does not give
>you carte blanche to use carabiners that have been dropped a significant
>distance. Immediately retire any carabiner that is crooked, has deep indentations,
>or has a gate that doesn’t operate smoothly."
>

On 9/11/2011 vonClimb wrote:
>A few years ago a dropped a quick drawer off a 100m cliff. Obviously it
>was to never be used again.
>
>However I ran into a guy who works for metolius in oregon. His job is
>quality control of beaners and cams. When these are manufactured he would
>inspect the metal components under microscope looking for any of these
>microfractures greater than some critical size. If found they would either
>try recover the part or throw it out.
>
>I gave him my draw to have a look at and he immediately spotted a small
>indent on one of the beaners that looked dubious. He said it was especially
>bad because it was on the inner edge of the beaner which gets loaded in
>tension and hence pulls any microcracks open.

What i'm getting from this is that its all too variable dependant to predict (height, landing on grass/rock, where the impact is etc). Even if 1 out of 1000 drops causes damage that could reduce the integrity which isn't visible to the naked eye would you want to risk using that 1 draw? I certainly wouldn't.