External Hex, Internal Hex, Internal Torx, TX, Hex
AF, Metric, Torx, Imperial, SAE
9/16 ", 9 mm, 3/8 ", 13 mm, 19 mm
12.5, 25.4, 19.05, 6.35, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide