Internal Hex, External Hex, Internal Torx, Hex, TX
Imperial, AF, Metric, Torx, SAE
4 mm, 7/32 ", 5/16 ", 11/16 ", 25 mm
25.4, 6.35, 12.5, 9.53, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide