Taken from "Understanding Carabiners":
Get Outdoors - Carabiners: Understanding Carabiners Quote:
|
Remember that a carabiner that has fallen off a cliff onto a hard surface has probably suffered hairline fractures and should be retired. Resist using such a "treasure" found at the base of a climb. In fact, you should resist using any critical climbing equipment if you don't know its history. Ropes, harnesses, runners, carabiners, protection pieces, and belay devices are all vital links in your chain of protection. Secondhand equipment, whether found or passed along without an account of its use, increases the possibility of a weak link in the chain you depend on for safe climbing.
|
At the following link you can find the following quote:
Rock and Ice Forum // View topic - Hairline fractures in carabiners Quote:
I'd retire any piece of gear dropped from half a pitch up or higher, and onto a hard surface. This is just a gut feeling, though. Most climbing gear is aluminum, and aluminum is ductile, and isn't prone to cracking. It will bend and ding, but getting it to crack from a simple drop is very difficult. Some (though rare) aluminum gear is cast. I have and still use a pair of Jumars from the early 1980s that are made of cast aluminum. Cast-metal gear is much more likely to fracture than forged gear. If I were to drop those jumars from higher than just a few feet, I'd replace them, something I should probably do anyway.
The trouble with dropped gear is that you never really know unless you either test it to destruction or get it x-rayed. Since neither option is especially practical, I recommend retiring any piece of equipment that was dropped and that you have the least bit of doubt about. Gear Guy has spoken!
|
Here's a site which tells how corrosion chemically affects 'biners, and how pitting occurs:
Aging Carabiners
And finally, here's a "mythbuster" thread,
which goes on to say, "well yeah, you should still check your gear, and it may be damaged actually, and there have been instances, and some types are more prone to it, etc etc..."
Myth#1
The Mythbuster part:
Quote:
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.?
|
The strangely CYA immediate followup:
Quote:
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 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.
|
Some mythbuster that is ....
George, do you have anything against people who wish to check their gear ANYWAY? JUST INCASE?
Besides, why suggest AGAINST people being extra cautious? Why do you care? If people want to check for fracture/corrosion/pitting.... whether it is present or not, that's pretty much up to them.
At the end of the day you have to climb on the gear that you own, be as safety conscious as you wish and as you're comfortable with, and don't let anyone convince you otherwise.
