The Precision Twist QC21PM jobber drill bit is a parabolic flute design, 135-degree radius split point, round shank drill bit made of HSS with an uncoated (bright) finish. It is suitable for drilling to a depth up to four times the diameter of the drill. Good for portable or machine drilling. The shank diameter is the same as the drill size. It was designed for drilling holes into a wide variety of metals and synthetic materials with best performance in steel and cast iron.
The QC21PM series has a wide land parabolic flute design that enhances chip (also called swarf) formation and evacuation. Coolant has a better flow to the drill point for heat dissipation, and can be used at higher speeds and feeds for increased productivity. It is recommended to use a constant heavy feed rate while drilling. This design has a reinforced web which provides increased drill strength and rigidity, and straighter closer tolerance holes. The uncoated finish helps keep costs down, yet provides acceptable performance in most situations. The finish helps increase chip flow in soft materials.
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 industry standards, which help ensure that drill bits around the world conform to the same specifications.
Precision manufactures machine tools under the following brands: Precision Twist, Precision Dormer, and Union Butterfield. They have locations around the world, and provide tools adhering to ANSI, NAS, and DIN standards.
.../ Precision Twist QC21PM High Speed Steel Jobber Drill Bit, Uncoated (Bright) Finish, Round Shank, Parabolic Flute, 135 Degree Point Angle, 13.00 mm / Steel Tool
