Internal Hex, External Hex, Internal Torx, Hex, TX
AF, Torx, Imperial, Metric, SAE
7/8 ", 12 mm, 19 mm, 5/16 ", 7/16 "
19.05, 38.1, 25.4, 9.53, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide