Th chains that APT uses are put together by my training partner Steve Slater. I can tell you that he makes sure these things are good quality. He also happens to make atlas stone molds, logs, etc. Very good guy, and an honest businessman.
http://www.slatershardware.com/
Not that most of you would be in the market for his stuff, but I can vouch for his chains.

Here is a vid of me using the chains on a log press (truthfully, a dumb idea)

And the man himself, Steve.