External Hex, Internal Hex, Internal Torx, Hex, TX
AF, Metric, Imperial, Torx, SAE
5.5 mm, 5/16 ", 9/16 ", 7 mm, 7/16 "
12.5, 19.05, 9.53, 6.35, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide