Power nut /screwdriver nut: Standard screw driver nuts Nonstandard screw driver nuts (customized shapes) Power nut /screwdriver nut: ... bit holders and quick changeconnectors for screwdriver bitsmaterial types:Cr-V 6150,8660,S2Surface treatment:sandblasted, tin-coating, ... Cu-coating, Ni-coating, Cr-coating, Zn-coatingHead types:PH, PZ, slot, Torx, square ...