Turnbuckle and Shackle Safety Factors for permanent use
Turnbuckle and Shackle Safety Factors for permanent use
(OP)
What safety factors and strength reduction factors (applied to the ultimate strength) do you use for shackles and turnbuckles that will be permanently installed in a structure?






RE: Turnbuckle and Shackle Safety Factors for permanent use
RE: Turnbuckle and Shackle Safety Factors for permanent use
RE: Turnbuckle and Shackle Safety Factors for permanent use
Basically the Steel Manual made the judgement of using a safety factor of three for permanent structures instead of five for this type of equipment but in the end it is up to engineering judgement.
RE: Turnbuckle and Shackle Safety Factors for permanent use
Anyway, you kind of hang yourself out to dry if you design for larger loads. You can draw all the chalkboard diagrams you want, but when you hand a jury a shackle stamped with "6,000 lbs" and start explaining why it's okay to load it to 10,000 lbs, it's a hard argument to make. Among other issues, you make it where you're the one guaranteeing the adequacy of that shackle for that load rather than the manufacturer.
A slightly-related issue that has come up in the past: When a lifting product specifically says, "Do not use this to lift people", can you use it to lift people? Engineering principles say "Sure", but it doesn't give you the warm fuzzy feelings doing it, either.
RE: Turnbuckle and Shackle Safety Factors for permanent use