Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, Torx, AF, Metric, SAE
5.5 mm, 7/16 ", 25 mm, 9 mm, 11/16 "
1-1/2, 1, 3/4, 1/4, 2-1/2
19.05, 25.4, 6.35, 9.53, 12.5
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide