External Hex, Internal Hex, Internal Torx, TX, Hex
AF, Imperial, Torx, SAE, Metric
5/16 ", 7/32 ", 5/8 ", 9/16 ", 35 mm
3/8, 1, 2-1/2, 1-1/2, 1/2
38.1, 9.53, 25.4, 6.35, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide