Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, AF, Metric, Torx, SAE
1/2 ", 7/16 ", 11/16 ", 26 mm, 1-1/2 "
6.35, 25.4, 19.05, 38.1, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide