Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, Metric, Torx, AF, SAE
1/4 ", 5 mm, 5/16 ", 34 mm, 11/16 "
2-1/2, 1/4, 3/8, 1-1/2, 1/2
38.1, 9.53, 19.05, 6.35, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide