The Precision Twist R40 stub length, 118-degree conventional point, general-purpose, round shank drill bit made of high-speed steel (HSS) with uncoated(bright) finish. It is suitable for drilling holes to a depth up to two-and-a-half times the diameter of the drill size. The shank diameter is the same as the drill size.
The 118-degree, conventional-point design is the most commonly accepted standard for drilling holes in a variety of material, such as metal, wood, and synthetics, with best performance in steel, stainless steel, cast iron, and unalloyed titanium. It comes with an uncoated (bright) finish, which helps keep costs down, yet provides acceptable performance in most situations. For drill bit sizes larger than 45/64 inch, the drills have a black oxide finish, which gives a strongly adhering surface treatment that acts to retain cutting fluid and prevent chip to tool welding, reducing the formation of a built-up edge.
Drilling, or hole making, is the most common metalworking operation in the world. Twist drill bits are the most common type of drill bit used. Twist drill bits are commonly used to drill holes with hand-operated drills, standalone drill presses, or lathes. The flutes of the drill bit act 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 chips up and away from the cutting edge. They are made to DIN 1897 industry standards (metric sizing), which helps ensure that drill bits around the world conform to the same specifications.
Precision manufactures machine tools under the following brands: Precision Twist, Precision Dormer, and Union Butterfield. They have locations around the world, and provide tools adhering to ANSI, NAS, and DIN standards.