Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, Torx, AF, Imperial, SAE
5/8 ", 7/8 ", 9/16 ", 5.5 mm, 11 mm
6.35, 25.4, 9.53, 38.1, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide