Internal Hex, External Torx, External Hex, TX, Hex
AF, Imperial, Torx, Metric, SAE
5/8 ", 3/16 ", 5/16 ", 7/16 ", 26 mm
2-1/2, 1-1/2, 1/4, 3/8, 1
38.1, 6.35, 25.4, 19.05, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Oxide, Black Phosphate