They have a black oxide surface treatement that is abrasion resistant, reduces chip welding and improves chip flow.1-3/16" 3MT HSS Undersized Shank Taper Shank Drill Bit Designed to perform in a broad range of materials in the iron and steel families.
For threading, a High Speed Steel Round Adjustable Die is desired for improved wear life. 1/2"-32x1-1/2" OD HSS Round Adjustable Die Special The slot is beveled so that when the dies are used in a machine holder the adjusting screw can be removed and adjustment made by the adjusting screws in the holder. Adjustment is obtained by a fine pitch screw which forces the sides of the die apart, or allows them to spring together.
Black oxide high-speed steel dill bits are ideal for production, maintenance or portable drilling jobs and are surface treated with abrasion-resistant black oxide.5 HSS Plug Tap and 10.