External Hex, Internal Torx, Internal Hex, TX, Hex
Imperial, AF, Torx, Metric, SAE
5.5 mm, 11/16 ", 5/8 ", 5 mm, 12 mm
12.5, 38.1, 6.35, 25.4, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide