Internal Hex, External Hex, Internal Torx, Hex, TX
Imperial, AF, Torx, SAE, Metric
5/8 ", 5.5 mm, 11/16 ", 25 mm, 23 mm
38.1, 25.4, 6.35, 9.53, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide