Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Torx, SAE, Metric
11/32 ", 4.5 mm, 9/32 ", 9/16 ", 5/16 "
6.35, 38.1, 19.05, 9.53, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide