Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, Torx, AF, Imperial, SAE
7/32 ", 5.5 mm, 5/16 ", 5/8 ", 11/16 "
2-1/2, 1-1/2, 3/8, 1/2, 1
38.1, 9.53, 6.35, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide