Internal Torx, External Hex, TX, Hex, External Torx
Imperial, AF, Metric, Torx, SAE
5/16 ", 3/16 ", 5.5 mm, 9 mm, 5/8 "
3/4, 3/8, 2-1/2, 1-1/2, 1/2
25.4, 6.35, 19.05, 12.5, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Phosphatized, Oxidised, Black Phosphate