Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, AF, Torx, Imperial, SAE
7/16 ", 9 mm, 5/16 ", 11/16 ", 1-1/2 "
19.05, 25.4, 9.53, 12.5, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide