The Precision Twist R09 jobber-length drill bit is a 118-degree conventional point, tanged shank drill bit made of HSS with a steam tempering finish. With general-purpose geometry, and conforming to automotive industry standards, the R09 series provides a secure holding drill bit for drilling into a wide variety of substances with best performance drilling into steel and cast iron. It is suitable for drilling to a depth up to six times the diameter of the drill.
The R09 series has a type N flute form, with a regular helix angle of 21 to 34 degrees. Steam tempering finish gives a strongly adhering blue oxide surface that acts to retain cutting fluid and prevent chip to tool welding, reducing the formation of a built-up edge. Spiral flutes act as a passageway for chip extraction from the hole and for coolant to enter the hole. Right-hand twist brings chips up and away from the cutting edge. The tang at the end of the taper is used for ejecting the drill bit from the spindle, with the aid of a drift pin.
Drilling, or hole making, is the most common metalworking operation in the world. Twist drill bits are the most common type of drill bit used. Twist drill bits are commonly used to drill holes with hand-operated drills, standalone drill presses, or lathes. The flutes of the drill bit act a passageway for chip extraction from the hole and for coolant to enter the hole. These drill bits have a right-hand twist that brings chips up and away from the cutting edge. They are made to ANSI (fractional sizing) industry standards, which help ensure that drill bits around the world conform to the same specifications.
Dormer Pramet manufactures cutting tools under the following brands: Precision Twist Drill, Dormer, Union Butterfield and Pramet. The company has locations around the world, and provides tools adhering to ANSI, NAS, and DIN standards.