6-48 UNEF( #6 x 48 tpi).- 8.8 high tensile steel.- Finished in a rich black zinc coating to help prevent rust.- Countersunk C/S head.- T15 Torx socket (T15 for strength of both tightening and the tool life).- OAL 9.85mm / 0.39”. Thread length 7.4mm / 0.29”.