External Hex, Internal Hex, Internal Torx, TX, Hex
Metric, Torx, AF, Imperial, SAE
7/32 ", 9/32 ", 13/16 ", 11/16 ", 25 mm
1, 1/4, 1-1/2, 2-1/2, 3/8
38.1, 19.05, 25.4, 6.35, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide