It's going back a while now but from memory the manufacturers recommendation (no 'standards' exist for testing bolts as far as I'm aware, they just have to be deemed safe by a 'competent person', so we generally just went by manufacturers rec.) was in the vicinity of 10% of SWL for 3 or 4 minutes? I could be way off in my memory there, I'll have a look in my old notes when I'm at my folks' place next |