Internal Hex, External Torx, Internal Torx, Hex, TX
Imperial, AF, Torx, Metric, SAE
5/16 ", 7/16 ", 3/16 ", 5.5 mm, 11/16 "
38.1, 9.53, 6.35, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide