External Hex, Internal Hex, Internal Torx, TX, Hex
Metric, AF, Torx, Imperial, SAE
11/16 ", 13/16 ", 9 mm, 5/16 ", 1/2 "
38.1, 9.53, 12.5, 19.05, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Oxide, Black Phosphate