Recessed head screw

A recessed head screw comprising a shank, a head disposed at one end of said shank, a drilling portion disposed at another end of said shank, and a plurality of threads spirally disposed on said shank about an axis, with said head including a top face and a bottom face connected between said top face and said shank, with said top face having a socket portion formed thereon;

• wherein said socket portion has a driving recess formed therein and a driving socket formed between said driving recess and said top face, with said driving recess enclosed by a plurality of interconnected walls and having cross sections perpendicular to the axis, with said driving socket communicating with said driving recess, with the driving socket having cross sections perpendicular to the axis and of equal size from the driving recess to the top face, with shapes of the cross sections of the driving socket being outside of and different than shapes of the cross sections of the driving recess, said-driving socket having a circumscribed circle diameter value greater than a circumscribed circle diameter value of said driving recess and less than or equal to 1.2 times the circumscribed circle diameter value of said driving recess, said driving socket defining a driving socket depth at least 0.15 times the circumscribed circle diameter value of said driving recess.