Lifting chain is generally tensile tested whereas general use chain is
just fabricated and shipped. Using roller chain as an example (like
forklifts use) because that's what I work with....A # 80 chain has an
AVERAGE ultimate strength of 14,500 pounds. The average link wont die
until you are at that level. However, any individual link may die at 1
pound. Hence, the need for a good safety factor when using chain for
power transmission service (among other reasons).

But lifting is CRITICAL. Therefore any chain rated for lift is tested
in (usually) a hydraulic pull bench for an amount of tension greater
than the "average" ultimate strength rating of everyday chain.
Sometimes they also cycle it a few times to make sure things aren't
coming loose. This insures that, when tested to 10,000 pounds, a chain
is assured of being good to lift some lesser amount (usually a safety
factor of about 4).

Things like poor plating and poor heat treating can really screw up a
chain. On transmission applications, it's not usual for someone to die
or receive a severe injury from such a screw up. On lifting
applications, it is. It's gotta be tested on lift applications or you
may be the guy to hit the one link that is below average.

I've focused on roller chain but it's essentially the same for
link-chains used for lift.

Koz



RainLover wrote:

I've been looking at chain lately (3/8") and I've noticed something that so far, every hardware guy
says he's never seen before. On the box of chain, without exception, they all say "DO NOT use for
lifting or any situation where a life could be endangered if the chain fails.

Tell me if I'm wrong here, but what in the hell could a person use a 3/8" chain for that wasn't
potentially dangerous. If the chain has a rating of 6,500 pounds and breaks, someone is going to be
around!!!

Is this a case of lawyers being in charge of chain-making or is there actually different chain that
is approved for lifting and all the stuff at H.D., Lowes, Ace is made for something else... what I
don't know.

Any suggestions? :-)

James, Seattle

www.jameskelseystudios.com