The Precision Twist R58 Jobber-length, uncoated, general-purpose, round shank drill bit drills holes into a wide variety of metals and synthetic materials with best performance with steel, stainless steel, cast iron, titanium, and nickel. It can drill to a depth up to one and a half times the diameter of the drill size. Flute length is three inches, overall length is six inches, with a half-inch, reduced shank. Combination steam tempered (sometimes called black oxide) and uncoated finish improves lubricity, resists corrosion, and will not chip or flake off. Black oxide also helps to prevent buildup and welding of material on the cutting edge when working with iron and steel. Reduced shanks are smaller than the drill diameter, so they can drill holes larger than the typical chuck capacity. These are sometimes called Silver & Deming drills as they were made by Silver & Deming in the late 1800s. Now, this refers to any reduced shank twist drill bit. 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 ANSI (fractional sizing) standards, which help 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.
