Internal Hex, External Hex, Internal Torx, TX, Hex
AF, Imperial, Torx, Metric, SAE
5/16 ", 7/16 ", 5/8 ", 11/16 ", 23 mm
1/4, 1-1/2, 1, 2-1/2, 1/2
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