Thank you for your replies,
I use SF=3 for general purpose spreader bars (From ASME BTH category B lifter, service class 0)
For manbaskets I use SF=5 (From CSA Z150)
So I usually use SF=5 for people underneath a load because the same risk is involved for a manbasket. But I have noticed others use 3,6,8, it is all over the place, so I was curious what other people use and why.
Does anyone know what safety factor automotive lift designers use? I tried looking it up but was not able to find it.
A.M.