Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Metric, Torx, SAE
5.5 mm, 5 mm, 3/16 ", 7 mm, 1-1/2 "
3/4, 1-1/2, 3/8, 1/4, 1/2
38.1, 25.4, 6.35, 19.05, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide