External Hex, Internal Hex, Internal Torx, Hex, TX
AF, Torx, Imperial, SAE, Metric
7/8 ", 5/16 ", 26 mm, 23 mm, 25 mm
6.35, 12.5, 38.1, 19.05, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide