Precision Twist 4ASM High Speed Steel Short Length Drill Bit, Black Oxide Finish, Round Shank, Spiral Flute, 135 Degree Point Angle, 11.20mm (Pack of 6)

The Precision Twist 4ASM short-length drill bit, is a round shank bit made of HSS with a steam tempering finish. It is suitable for drilling to a depth up to four times the diameter of the drill. The shank diameter is the same as the drill size. It is best used for drilling into steel, stainless steel, cast iron and titanium. While the 4ASM series was designed for the aircraft industry, it also works well for drilling into a variety of materials. The short length and 135-degree split-point drill geometry provide a stable and rigid platform and ensure a more accurate hole by reducing walking when the hole is started. Steam tempering finish 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. The finish retains lubricant to aid in wear resistance and chip flow. The 4ASM series has a type N flute form, with a regular helix angle (21 to 34 degrees). Uncoated (bright) tools have no finish or coating. They are a common choice for general use applications. The short-stub length has more rigidity for drilling straighter, shallower holes than Jobber-length bits. Spiral flutes act as a passageway for chip extraction from the hole and for coolant to enter the hole. Right-hand twist brings chips up and away from the cutting edge. Drilling, or hole making, is the most common metalworking operation in the world and twist drill bits are the most common type of drill bit. They can be used in hand-operated drills, standalone drill presses, or a lathe. The flutes of the drill bit act as a passageway for chip extraction from the hole and for coolant to enter the hole. These drill bits have a right-hand twist that brings the chips up and away from the cutting edge. They are made to DIN 1897 (metric sizing) and NAS 907 type C industry standards, which ensure that drill bits around the world conform to the same specifications. 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.

• NAS 907 type C standards, for use in the aerospace industry
• Short-length (also called stub), for better rigidity and increased strength
• Steam tempering (also called black oxide), to retain cutting fluids and to prevent chip-to-tool welding
• 135-degree split-point angles is self-centering, to reduce walking, to use with hard materials, and to reduce pressure on cutting edges
• High-speed steel (HSS), for use on a wide variety of materials