The Dormer A901 Spectrum jobber-length drill bit is a 130-degree, PFX point, round shank drill bit made of cobalt steel. It can drill holes up to six times the diameter of the drill. The shank diameter is the same as the drill size. It is recommended to use ER collets for size ranges of: 1/16” - 5/8”, A - Z, 53 - 1, 1.5 - 16.0 mm.
The A901 series has a type W flute form, with a fast helix angle of 35 to 45 degrees, and are 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 six times the drill diameter deep holes, thus offering improved efficiency and increased productivity. Cobalt steet combines toughness and hardness needed for deep hole drilling. The parabolic design, combined with a parallel thinned web, allows for efficient chip removal.
Aluminum chromium nitride (AlCrN) also known as Smooth-Flow coating, provides hardness and better resistance to chemical breakdown in high-heat applications than TiAlN, TiCN, and TiN coatings.This coating is suitable for use on ductile cast iron and carbon steel. The spiral flutes act as a passageway for chip removal and for coolant to enter the hole. The right-hand twist brings chips up and away from the cutting edge.
Cobalt steel is many times harder and stiffer than high-speed steel (HSS) and holds an edge longer, deflects less, and resistsheat better than HSS. These qualities allow it to run at higher speeds and feeds than tool steel.
Drill bits are cutting tools used to make holes in a range of materials. They are used in machines such as handheld portable drills, drill presses, machining centers, and lathes. Drill bits come in a variety of types and lengths. Twist drill bits are the most common type of drill bit. They are a round, twisted shaft, end-cutting tool with two or more cutting edges and two or more flutes. Jobber drill bits are the most common length of twist bit. They offer a good comprise of length and reach to work with the widest range of materials and applications.
Precision Dormer manufactures cutting tools under the brands Precision Twist, Dormer, and Union Butterfield. The company has locations around the world, and makes tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards.