Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, AF, Torx, Metric, SAE
5/16 ", 7/16 ", 5.5 mm, 25 mm, 9 mm
3/4, 1-1/2, 2-1/2, 1/2, 1
38.1, 6.35, 25.4, 19.05, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide