Drillco 1280C Series Cobalt Steel Aircraft Extension Drill Bit, Bronze Finish, Round Shank, Spiral Flute, 135 Degree Split Point, #39 Size (Pack of 6)

The Drillco 1280C series aircraft extension 12" long drill bit is made from cobalt steel with a bronze finish, has a 135-degree split point for use on high-tensile strength alloy steel, stainless steel, titanium, and other difficult to machine materials, and meets National Aerospace (NAS) 907 Type J and American National Standards Institute (ANSI) specifications. The aircraft extension drill bit is longer than long-length twist drill bits for difficult-to-reach areas. Cobalt steel provides extended tool life compared to high-speed steel drill bits, and maintains the tool's toughness and hardness in high drilling temperatures. The bronze finish lubricates the drill bit and provides wear resistance. The self-centering 135-degree split point penetrates hard material without a pilot hole and produces smaller chips that reduce clogging compared to a 118-degree point. The round shank accommodates most drill chucks.Drill bits are cutting tools used to make holes in a range of materials using machines such as handheld portable drills, machining centers, and lathes. Drill bits come in a variety of lengths and types, the most common of which is the twist drill bit. The round, twisted shaft of the twist drill bit typically has two cutting edges and flutes. The helical twist of the flutes brings chips up and away from the cutting edges and allows for coolant to reach the cutting edges. Jobber length twist drill bits, the most common length of twist drill bit, offer a good compromise of length and reach for the widest range of materials and applications. Mechanic's length twist drill bits (also called maintenance length) are a little shorter than jobber length and less prone to deflection when drilling. Short length twist drill bits (also called stub or screw-machine length) are the shortest and stiffest twist drill bits, helping to reduce the chance of deflection or breakage when drilling. Reduced shank twist drill bits (also called Silver and Deming drill bits) have a shank that is smaller in diameter than its shaft, permitting drilling machines with a 1/4", 1/2", or 3/4" drill chuck to create large holes. Long length twist drill bits (also called taper length) are a little longer than jobber length, allowing for deeper holes and longer reach. Extra-long length twist drill bits (also called extension) are longer than long length twist drill bits for greater reach or for drilling deeper holes.Drillco manufactures cutting tools such as drill bits, reamers, taps, dies, annular cutters, end mills, and burs. The company, founded in 1978, is headquartered in Baton Rouge, LA.

• Aircraft extension drill bit meets NAS 907 Type J specifications and has a 12" overall length for drilling hard-to-reach areas
• Designed for drilling high-tensile strength alloy steel, stainless steel, titanium, and other difficult to machine materials
• Cobalt steel provides extended tool life compared to high-speed steel drill bits when drilling hard materials
• Bronze finish lubricates the drill bit and provides wear resistance
• Self-centering 135-degree split point penetrates hard material without a pilot hole and produces small chips to reduce clogging