Internal Hex, Internal Torx, External Hex, TX, Hex
Metric, AF, Imperial, Torx, SAE
7/16 ", 7/8 ", 3/16 ", 5.5 mm, 9 mm
12.5, 19.05, 25.4, 6.35, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide