Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Torx, Metric, SAE
5/16 ", 5/8 ", 5.5 mm, 7/16 ", 26 mm
3/8, 3/4, 2-1/2, 1/2, 1/4
12.5, 9.53, 6.35, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide