Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, Metric, AF, Torx, SAE
5.5 mm, 5/8 ", 9/16 ", 3/16 ", 11/16 "
3/4, 3/8, 2-1/2, 1/4, 1/2
12.5, 6.35, 9.53, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide