Internal Hex, External Hex, Hex, TX, External Torx
Imperial, AF, Torx, SAE, Metric
3/16 ", 8 mm, 5/16 ", 25 mm, 33 mm
12.5, 9.53, 19.05, 25.4, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Oxide, Black Phosphate