Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, Metric, AF, Torx, SAE
6 mm, 5/16 ", 9/16 ", 5.5 mm, 11/16 "
12.5, 25.4, 38.1, 9.53, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide