Internal Hex, External Torx, External Hex, Hex, TX
Imperial, Torx, AF, Metric, SAE
12 mm, 15 mm, 18 mm, 11/16 ", 23 mm
2-1/2, 1-1/2, 1/2, 3/4, 3/8
38.1, 25.4, 6.35, 19.05, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide