Precision Twist QC91PM High Speed Steel Long Length Drill Bit - Uncoated Bright Finish, Round Shank, Parabolic Flute, 135° Point Angle, 8.20mm (6-Pack) - Perfect for Metalworking, Woodworking, and DIY Projects

The Precision Twist QC91PM taper-length 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 six 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 QC91PM 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, while providing 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 DIN 340 (metric sizing) industry standards, which helps 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.

Parabolic flute design offers enhanced chip removal, coolant flow to the drill point, and heat dissipation

Taper-length drill bits have longer flutes and overall lengths than jobber drill bits, for deeper holes

135-degree radius split-point is self-centering, reduces walking, good for hard material, and reduces pressure on cutting edges

Uncoated (bright) finish, economical and useful with a wide range of drilling materials

High-speed steel (HSS), for use on a wide variety of materials