External Hex, Internal Torx, Internal Hex, TX, Hex
AF, Imperial, Torx, SAE, Metric
5.5 mm, 5/8 ", 11/16 ", 29 mm, 1-1/2 "
1, 1/4, 2-1/2, 1-1/2, 3/8
6.35, 9.53, 19.05, 25.4, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Phosphatized, Oxidised, Black Phosphate, Black Oxide