External Hex, Internal Hex, Internal Torx, TX, Hex
Imperial, AF, Metric, Torx, SAE
15/16 ", 9/16 ", 5.5 mm, 5/16 ", 26 mm
3/4, 1, 1-1/2, 2-1/2, 1/2
9.53, 19.05, 38.1, 25.4, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide