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