Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Torx, SAE, Metric
3/16 ", 16 mm, 3/8 ", 11/16 ", 3/4 "
1-1/2, 2-1/2, 1/2, 1/4, 3/8
9.53, 38.1, 12.5, 25.4, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide