Internal Hex, Internal Torx, External Hex, Hex, TX
AF, Torx, Imperial, Metric, SAE
4 mm, 5.5 mm, 5 mm, 9/16 ", 11/16 "
1/4, 1-1/2, 3/4, 2-1/2, 1/2
12.5, 25.4, 19.05, 9.53, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide