External Hex, Internal Torx, Internal Hex, TX, Hex
Imperial, Metric, AF, Torx, SAE
13 mm, 7/16 ", 11/16 ", 9 mm, 23 mm
3/4, 1/4, 2-1/2, 1-1/2, 1/2
9.53, 12.5, 19.05, 6.35, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide