Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Torx, Metric, SAE
7/16 ", 13 mm, 16 mm, 5/16 ", 9 mm
38.1, 9.53, 6.35, 12.5, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide