Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, AF, Imperial, Torx, SAE
13/16 ", 12 mm, 5/16 ", 25 mm, 35 mm
1/4, 3/4, 2-1/2, 1/2, 3/8
38.1, 25.4, 19.05, 9.53, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide