The Precision Twist R51 long length, 118-degree conventional point, general-purpose round shank drill bit made of high-speed steel (HSS) with uncoated(bright) finish is suitable for drilling holes to a depth up to six 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. It comes with an uncoated 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. This finish 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.
and away from the cutting edge. They are made to ANSI (fractional) industry standards, which help ensure that drill bits around the world conform to the same specifications.