Internal Hex, Internal Torx, External Hex, Hex, TX
Imperial, AF, Torx, SAE, Metric
7/16 ", 7/8 ", 3/16 ", 5.5 mm, 9 mm
25.4, 6.35, 38.1, 19.05, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide