Internal Hex, Internal Torx, External Hex, Hex, TX
AF, Imperial, Metric, Torx, SAE
4.5 mm, 4 mm, 9/32 ", 5.5 mm, 9/16 "
1/4, 3/4, 2-1/2, 1/2, 3/8
25.4, 9.53, 19.05, 6.35, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide