External Hex, Internal Hex, Internal Torx, TX, Hex
AF, Imperial, Torx, Metric, SAE
7/32 ", 9/32 ", 5.5 mm, 8 mm, 11/16 "
38.1, 6.35, 9.53, 19.05, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide