Found this page while tootling online:
http://www.balancecommunity.com/knowledge/all-about-shackles/
Has a few load tables and things on three version of shackles.
It may be available elsewhere, I just found it here.
http://www.balancecommunity.com/knowledge/all-about-shackles/
Has a few load tables and things on three version of shackles.
It may be available elsewhere, I just found it here.