External Hex, Internal Hex, Internal Torx, TX, Hex
AF, Imperial, Torx, Metric, SAE
7/16 ", 11/16 ", 13/16 ", 36 mm, 25 mm
1-1/2, 1, 2-1/2, 1/2, 1/4
38.1, 6.35, 25.4, 19.05, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide