Internal Torx, Internal Hex, External Torx, TX, Hex
Imperial, AF, Metric, Torx, SAE
5.5 mm, 17 mm, 5/16 ", 9 mm, 11/16 "
2-1/2, 1-1/2, 1/2, 3/8, 1
38.1, 25.4, 6.35, 19.05, 12.5
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide