Cleveland 3780 Cobalt Steel Jobbers' Length Drill Bit, Short Flute, Black Oxide, Round Shank, 135 Degree Split Point, 7/64" (Pack of 10)
The Cleveland 3780 short flute jobber length, high-speed steel (HSS) containing cobalt drill bit has a 40-degree helix angle, with a 135-degree split-point and black oxide surface treatment, which is designed for heavy-duty drilling applications. Several features such as extra heavy web for increased rigidity, high helix angle for efficient chip removal, and a preferred drill bit point geometry for drilling into work-hardened stainless steels, combined with short flutes, offer a high performance drill bit for common aircraft maintenance duties or industrial usage. Conforms to NAS 907 type D specifications. Round shanks into a wide range of tool-holders.
The 3780, also known as Q-AMD Aircraft Maintenance series can be used on most materials, it is most suitable for drilling into various steels such as tool steel, steel alloys, work-hardened stainless steel and inconel. Black oxide, also called steam oxide, gives a strongly adhering blue oxide surface that acts to retain cutting fluid and prevent chip to tool welding, reducing the formation of a built-up edge. 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. The higher, also called faster helix provides greater lifting power for chips than a slower or lower helix angle. 135-degree drill point reduces walking when starting a hole and penetrates more easily than a convention point. Round shanks allow use with a wide variety of tool holding systems. While the 3780 series was designed for the aircraft industry, it also works well in other industries. Made from HSS containing cobalt which can be run at faster speeds and stays sharp longer than HSS tools, while offering resistance to heat and abrasion.
The tolerances for various aspects of the Cleveland drill bits are: drill diameter range through 1/8†+0.0000â€/-0.0005â€, over 1/8†to 1/4†+0.0000â€/-0.0007â€, over 1/4†through 1/2†+0.0000â€/-0.0010â€, over 1/2†to 1†+0.0000â€/-0.0012â€, over 1†to 2†+0.0000â€/-0.0015â€, over 2†to 3-1/2†+0.0000â€/-0.0020â€; drill overall length and flute length #80 through 1/8†+0.1250â€/-0.0626â€, over 1/8†to 1/2†+0.1250â€/-0.1250â€, over 1/2†to 1†+0.2500â€/-0.1250â€, over 1†to 2†+0.2500â€/-0.2500â€, over 2†to 3-1/2†+0.3750â€/-0.3750â€; 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 0.0020â€, over 1/8†to 1/4†total indicator variation 0.0030â€, over 1/4†to 1/2†total indicator variation 0.0040â€, over 1/2†to 1†total indicator variation 0.0050â€, over 1†to 3 1/2†total indicator variation 0.0060â€.
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 compromise of length and reach to work with the widest range of materials and applications.
Greenfield Industries, which are a part of Top-Eastern Group, is one of the largest manufacturers of twist drills. They also manufacture cutting tools and related products under the following brands: Cleveland, Chicago-Latrobe, Cle-Line, Vermont Tap & Die, Bassett, Putnam Tools, Geo Met RJC, H & G, Vers-O-Tool, and Acme-Fette. The company has locations around the world, and provides tools adhering to ANSI, NAS, and DIN standards.