Drillco 3500E Series High-Speed Steel Center Countersink, Uncoated (Bright) Finish, 5/16" Body Diameter, 60 Degrees Angle, 4" Size

Drillco center drill bit when metal parts are machined on centers, as in turning or cylindrical grinding, it is always necessary to drill and countersink the center holes to serve as seats or bearings in the machine centers. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. Uncoated tools feature just the base substrate without any additional treatment or coatings and are suitable for a wide range of applications. When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging. Right-hand cut tools have a cutting action that engages when they are run in a clockwise direction.