Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Torx, Metric, SAE
7/32 ", 7/8 ", 5.5 mm, 5/8 ", 9/16 "
38.1, 25.4, 9.53, 6.35, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide