Internal Hex, Internal Torx, External Hex, Hex, TX
AF, Imperial, Torx, Metric, SAE
5/16 ", 7/16 ", 11/16 ", 25 mm, 1-1/2 "
1/4, 3/4, 1, 2-1/2, 1-1/2
25.4, 6.35, 9.53, 19.05, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide