Internal Hex, External Hex, Internal Torx, TX, Hex
AF, Imperial, Torx, SAE, Metric
7/8 ", 3/16 ", 5/16 ", 23 mm, 9 mm
38.1, 19.05, 12.5, 6.35, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Phosphated, Oxidised, Black Phosphate, Black Oxide