External Hex, Internal Torx, Internal Hex, TX, Hex
Imperial, Metric, AF, Torx, SAE
7/32 ", 9/32 ", 5.5 mm, 7/8 ", 7 mm
25.4, 19.05, 9.53, 6.35, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Oxide, Black Phosphate