External Hex, Internal Torx, Internal Hex, Hex, TX
Metric, Torx, AF, Imperial, SAE
5/16 ", 7 mm, 9/32 ", 15/16 ", 13/16 "
38.1, 9.53, 6.35, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Oxide, Black Phosphate