Internal Hex, External Torx, External Hex, TX, Hex
AF, Torx, Imperial, Metric, SAE
5/16 ", 7/32 ", 9/32 ", 12 mm, 3/16 "
2-1/2, 1/4, 3/8, 1/2, 3/4
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