Internal Hex, External Hex, TX, Hex, External Torx
AF, Imperial, Torx, Metric, SAE
3/16 ", 4 mm, 5/16 ", 6 mm, 9/16 "
1/4, 1-1/2, 2-1/2, 1/2, 3/4
38.1, 6.35, 19.05, 9.53, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide