Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, AF, Torx, SAE, Metric
3/16 ", 5.5 mm, 7/16 ", 5/8 ", 36 mm
3/4, 2-1/2, 3/8, 1-1/2, 1/2
38.1, 9.53, 6.35, 19.05, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide