Internal Hex, Internal Torx, External Hex, Hex, TX
Imperial, AF, Torx, Metric, SAE
15/16 ", 3/16 ", 5.5 mm, 5/16 ", 1-1/2 "
1-1/2, 2-1/2, 3/8, 1/2, 3/4
38.1, 9.53, 19.05, 6.35, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide