i imagine
@egilson1 may post full results at some
point, but . . .
1/4" Grade 30
Proof Coil chain is usually rated with a Safe Working Load (
SWL) of 1,250 or 1,300 pounds. In their test it failed at 6,700 pounds. That is 5.15 times greater than the
SWL or a factor of over 5.
A 5/16"
Shackle is usually rated to 3/4 of a ton or 1,500 pounds. If you strain your eyes you can see the one tested was marked
WLL 3/4. '
WLL' means Working Load Limit, another way to say
SWL. In their test it failed at 7,945 pounds. That is 5.3 times greater that the
SWL.
A lot of people knock 'Chinese' stuff as inferior junk, but a 5:1 ratio of breaking
point to
SWL is pretty typical for the industry. We have an importer in our area who brings
in one or two containers a week of chain,
wire rope,
etc and repackages onto smaller reels or buckets and sells nationwide. They test a sample from every spool of
wire rope and vat of chain and randomly test connectors like shackles. They tell me their suppliers are almost always providing things that fail at over 5 times the
SWL. And if something doesn't pass, there is a scrap metal dumpster out back and I've seen whole spools or
wire rope in it.
The important part is to know who you're buying from and that they're a quality vendor. It's not hard to paint the pin of
shackle red and try to pass it off as a genuine
Crosby brand item.
And I don't mean to offend anyone or sound like a grumpy old man who is disappointed with the way some colleges are cranking out techs who don't know the basics, BUT if you don't know what the numbers on a
shackle mean or where to find the
SWL for chain or know the relationship between
SWL and breaking
point . . .