Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Metric, Torx, SAE
3/16 ", 19 mm, 1/4 ", 5/16 ", 11/16 "
1/2, 1/4, 3/4, 1-1/2, 3/8
12.5, 25.4, 9.53, 19.05, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide