Internal Hex, External Hex, TX, Hex, 6-Point
AF, Metric, Torx, Imperial, SAE
7/8 ", 9 mm, 5/16 ", 9/16 ", 3/4 "
19.05, 9.53, 25.4, 38.1, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide