Internal Hex, Internal Torx, External Hex, TX, Hex
Metric, AF, Imperial, Torx, SAE
5/16 ", 7/16 ", 3/16 ", 5/8 ", 9/16 "
19.05, 9.53, 6.35, 12.5, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide