Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, Torx, AF, Imperial, SAE
4.5 mm, 5 mm, 9 mm, 1-1/2 ", 11/16 "
19.05, 9.53, 12.5, 25.4, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide