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Dormer A921 Cobalt Steel Short Length Drill Bit, AlCrN Coating, Round Shank, 130 Degree Special Point, 6.80 mm
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Dormer A921 Cobalt Steel Short Length Drill Features
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Stub length, for the greatest stiffness of the various drill bit sizes
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130-degree point angle for centering and to reduce pressure on cutting edges
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High-speed steel (HSS) containing cobalt is a combination of toughness and hardness, for use on drilling into hard substances
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Aluminum chromium nitride (AlCrN) coating, to help reduce friction, for efficient chip removal, and to help extend tool life
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Round shanks, for use on a variety of tool-holding systems
About Dormer A921 Cobalt Steel Short Length Drill
The Dormer A921 stub-length drill bit is a 130-degree, PFX point, round shank drill bit made of HSS and cobalt. It can drill holes up to three times the diameter of the drill. The shank diameter is the same as the drill size. The A941 series has a type W flute form, with a fast helix angle of 35 to 45 degrees, and is most suitable for drilling into steel, stainless steel, titanium, nickel, and alloyed aluminum. This design allows for single-pass drilling, which helps eliminate the need for pecking in up to three times the drill diameter deep holes, thus offering improved efficiency and increased productivity. The stub length offers more stiffness than a jobber-length drill bit. The composition of HSS and cobalt offers a 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 evacuation. With proper cutting conditions and rigid machine setup, holes to H10 tolerance can consistently be achieved. It has an Aluminum chromium nitride (AlCrN) coating (also called Smooth-Flow coating), which helps increase chip removal and helps in wear resistance, and combines hardness in high heat with high oxidation resistance. This coating is most suitable for use on ductile cast iron and carbon steel. The spiral flutes act as a passageway for chip extraction from the hole and for coolant to enter the hole. The 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 ANSI and DIN 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.
