Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, AF, Imperial, Torx, SAE
6 mm, 7/16 ", 9/16 ", 12 mm, 13/16 "
1/4, 1, 2-1/2, 1-1/2, 1/2
6.35, 12.5, 19.05, 9.53, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide