Internal Hex, Internal Torx, External Hex, Hex, TX
Imperial, Metric, AF, Torx, SAE
5.5 mm, 11/16 ", 7/16 ", 3/16 ", 26 mm
38.1, 9.53, 25.4, 19.05, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide