Internal Hex, Internal Torx, External Hex, TX, Hex
Metric, Torx, Imperial, AF, SAE
7/8 ", 13 mm, 9/16 ", 9 mm, 26 mm
38.1, 25.4, 19.05, 9.53, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide