Internal Hex, Internal Torx, External Hex, TX, Hex
Metric, AF, Imperial, Torx, SAE
4 mm, 5/16 ", 6 mm, 7/16 ", 13/16 "
38.1, 9.53, 6.35, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Oxide, Black Phosphate