Screws where the dimension L is < B are threaded up to the head. The screw length or thread length is specified by the dimension L. Screws where L is > B have a shaft.
Steel or stainless steel (A 2)
Steel grade 8.8, black or electro zinc-plated.
Steel grade 10.9, black or electro zinc-plated.
Stainless steel A 2-70, bright.