Dormer A978 Cobalt Steel Extra Long Length Drill Bit, Parabolic Flute, PFX Style, Uncoated (Bright) Finish, Round Shank, 130 Degree Point Angle, 4.00mm

The Dormer A978 extra-length drill bit is a 130-degree, PFX point, round shank drill bit made of HSS and cobalt. It can drill holes up to 15 times the diameter of the drill. The shank diameter is the same as the drill size. Best performance in steel but also works in a wide variety of materials. The A978 PFX series allows for single pass drilling, which eliminates the need for pecking in up to 10 times the drill diameter deep holes, thus offers improved efficiency, and increased productivity. The composition of HSS and cobalt is a good combination of toughness and hardness needed for deep hole drilling. The parabolic design, combined with a parallel thinned web, allows for smooth and efficient chip (also called swarf) evacuation. With proper cutting conditions and rigid machine setup, holes to H10 tolerance can consistently be achieved. It has an uncoated finish and Smooth-Flow coating, which helps increase chip removal and helps in wear resistance. 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. Made of HSS with cobalt which is many times harder and stiffer than HSS, will hold an edge longer, and will deflect less than HSS. These are also more resistant to heat than HSS. These qualities allow it to run at higher speeds and feeds. They are made to DIN 1869 series 2 (metric sizing) industry standards, which help ensure that drill bits around the world, conform to the same specifications. 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. 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.

• Extra-length drill bits have longer flutes and overall lengths than Jobber drill bits, for deeper holes
• 130-degree point angle has good centering capabilities and reduces pressure on cutting edges
• High-speed steel (HSS) containing cobalt is a good combination of toughness and hardness, for use on drilling through hard substances
• Bright finish with Smooth-Flow coating reduces coefficient of friction, has efficient chip evacuation and extends tool life
• Round shanks, for use on a variety of tool-holding systems