Internal Hex, External Torx, External Hex, TX, Hex
Imperial, Metric, AF, Torx, SAE
5/16 ", 5 mm, 12 mm, 9/16 ", 1-1/2 "
25.4, 6.35, 9.53, 19.05, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide