Internal Hex, Internal Torx, External Hex, Hex, TX
Imperial, AF, Torx, Metric, SAE
4.5 mm, 9/32 ", 5.5 mm, 9/16 ", 11/16 "
1/4, 1-1/2, 3/4, 1, 2-1/2
38.1, 25.4, 9.53, 19.05, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide