Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, AF, Torx, Imperial, SAE
5/16 ", 7/16 ", 5/8 ", 5 mm, 9/16 "
3/4, 1-1/2, 1, 2-1/2, 1/2
6.35, 9.53, 25.4, 19.05, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide