Internal Hex, External Torx, External Hex, Hex, TX
Metric, AF, Imperial, Torx, SAE
5/16 ", 5/8 ", 5 mm, 9/16 ", 23 mm
1-1/2, 1, 2-1/2, 3/8, 1/2
19.05, 9.53, 38.1, 25.4, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide