I recently bought a box of 2" #8 steel woodscrews, made by Crown*, from HD . About one third of them stripped or broke off at the head when I was driving them into or taking them out of soft pine and 3/4" plywood. The driver bit fit the slots perfectly. I probaly should have pre-drilled the holes, but I thought they would work fine to screw a piece of plywood into a 2x4. Usuall I use drywall screws for that sort of thing, but I thought I'd try the wood screws... What a pain it was.
(*Crown Bolt? Something like that. )