Internal Hex, Internal Torx, External Hex, Hex, TX
AF, Imperial, Torx, SAE, Metric
5/16 ", 9/16 ", 3/16 ", 5.5 mm, 11/16 "
1/2, 3/4, 1, 1-1/2, 2-1/2
38.1, 19.05, 25.4, 9.53, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Phosphatized, Oxidised, Black Phosphate, Black Oxide