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