Internal Hex, External Torx, External Hex, TX, Hex
Imperial, AF, Metric, Torx, SAE
7/16 ", 6 mm, 5/16 ", 25 mm, 28 mm
1, 2-1/2, 3/8, 1-1/2, 1/2
25.4, 19.05, 6.35, 9.53, 12.5
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide