Internal Hex, External Hex, Internal Torx, Hex, TX
AF, Imperial, Metric, Torx, SAE
7/32 ", 9/32 ", 5/8 ", 5/16 ", 33 mm
1/4, 1, 2-1/2, 1-1/2, 3/4
19.05, 9.53, 25.4, 6.35, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Phosphated, Oxidised, Black Oxide, Black Phosphate