The Cleveland 2570 long length, four flutes, high-speed steel (HSS) drill bit has a 38-degree helix angle, with a 118-degree drill point and black oxide surface treatment, is designed for enlarging holes. These drills have a heavy and strong web that provides the extra rigidity which can enlarge an existing hole 60% over the original size hole. There are no cutting edges or other means of starting a hole. The shank diameter is the same as the drill size. It is recommended to run at two-thirds the speed and double the feed rate of a standard HSS drill.
While the 2570 series can be used on most materials, it is most suitable for drilling into various steels, and cast iron. Black oxide improves lubricity, resists corrosion, and resists flaking. It also helps prevent buildup and welding of material on the tool's cutting edge when machining iron and steel. Spiral flutes act as a passageway for chip extraction from the hole and for coolant to enter the hole. The twist of the flutes brings chips up and away from the cutting edge. Four flutes deliver a smoother finish surface finish than a three flute style. The faster helix provides greater lifting power for chips than a slower helix and is particularly suitable for deeper holes. The 118-degree drill point is the most common angle with a good compromise of performance across a wide range of materials. Round shanks allow use with a wide variety of tool holding systems. HSS is a common, general-purpose steel for cutting tools, offers toughness and shock resistance, and is compatible with a variety of materials.
The tolerances for various aspects of the Cleveland drill bits are: drill diameter range through 1/8” +0.0000”/-0.0005”, over 1/8” to 1/4” +0.0000”/-0.0007”, over 1/4” through 1/2” +0.0000”/-0.0010”, over 1/2” to 1” +0.0000”/-0.0012”, over 1” to 2” +0.0000”/-0.0015”, over 2” to 3-1/2” +0.0000”/-0.0020”; drill overall length and flute length #80 through 1/8” +0.1250”/-0.0626”, over 1/8” to 1/2” +0.1250”/-0.1250”, over 1/2” to 1” +0.2500”/-0.1250”, over 1” to 2” +0.2500”/-0.2500”, over 2” to 3-1/2” +0.3750”/-0.3750”; drill point angle diameter range 1/16” to 1/2” included angle 118 or 135 degrees +/-5 degrees, over 1/2” to 1 1/2” included angle 118 degrees +/-3 degrees, over 1-1/2” to 3-1/2” includes angle 118 degrees +/- 2 degrees; drill lip height diameter range 1/16” to 1/8” total indicator variation 0.0020”, over 1/8” to 1/4” total indicator variation 0.0030”, over 1/4” to 1/2” total indicator variation 0.0040”, over 1/2” to 1” total indicator variation 0.0050”, over 1” to 3 1/2” total indicator variation 0.0060”.
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. Long length bits (also called taper length) are twist bits that are a little longer than jobber length, allowing for deeper holes and longer reach.
Greenfield Industries manufactures tools under the brand names Cleveland, Chicago-Latrobe, Cle-Line, Vermont Tap & Die, Bassett, Putnam Tools, Geometric, Vers-O-Tool, H & G, and Acme-Fette. The company owned by Top-Eastern Group and headquartered in Seneca, SC, makes tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards.