Internal Hex, Internal Torx, External Hex, Hex, TX
AF, Torx, Metric, Imperial, SAE
9/16 ", 4.5 mm, 3/16 ", 5.5 mm, 5/8 "
38.1, 19.05, 6.35, 9.53, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide