Internal Hex, External Hex, Internal Torx, TX, Hex
AF, Metric, Imperial, Torx, SAE
4 mm, 12 mm, 5/16 ", 5/8 ", 1-1/2 "
1/4, 1-1/2, 1, 2-1/2, 3/4
19.05, 9.53, 25.4, 6.35, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide