Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, Metric, AF, Torx, SAE
3/16 ", 5/16 ", 7/16 ", 5/8 ", 25 mm
1-1/2, 1, 1/2, 2-1/2, 3/8
38.1, 9.53, 6.35, 19.05, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide