>a CORRECTLY PLACED AND NEW 15 kN rated bolt is not really more likely to
>fail than a 30 kN bolt. With a bit of corrosion and repeat impacts the
>15 kN bolt is likely to fail far sooner than the larger bolt because it
>is no longer capable of sustaining the original forces. Even when half
>a strong as new a 25 or 30 kn bolt will still sustain most conceivable
Not really convinced. in engineering, a factor of safety (factor of ignorance) is used for designing stuff to spec. Eg, if you design a beam to hold 2 tons, you rate it for a 1 ton operating load. This is because a) people will push their 'luck' b) you're not 100% sure what's going on inside those materials. Was that Russian titanium appropriated from the missile factory or the teapot factory?
That's rated operating strenght.
Climbing gear and some other stuff, for various reasons is given a predicted failure rating. Eg, a 15kN bolt is expected to fail at 15kN.
refer to - adski's I think - post about a load testing machine (and Mikl's gorgeous sling testing method). The force at which some of the gear breaks sounds scary.
HOWEVER, how much gear have people busted? Lets have some good honest reports about what gear's failed and when.
>>Gear doesn't fail unless you make it. Nuff said.
Good call, Claw. I think generally rock breaks or gear zippers first.
I also use gear I find, sometimes snip off busted threads from damaged wires, used knotted socks for pro... Ok, I only use new explorer socks, not cheap soviet ones, but you get the point.
NOTE - sorry, just realised I misread your post. My point still stands, and sounds like we're making the same one.
Ooh, isn't this fun! Nothing like a controversy over hypothetically how likely we all are to crater. Check out Dave Jones's pro in 'Hard Grit'. Love your work dreadbrother!
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