The Precision Twist 2AB jobber drill bit is a conventional point, general purpose, round shank drill bit made of HSS with a steam tempering (also called black oxide) finish. It is suitable for drilling to a depth up to four times the diameter of the drill. Good for portable or machine drilling. The shank diameter is the same as the drill size. It was designed for drilling holes into a wide variety of metals and synthetic materials.
The 2AB series has a type N flute form, with a regular helix angle (21 to 34 degrees) is most commonly used drilling into steel or cast iron. An uncoated (bright) finish helps keep costs down, yet provides acceptable performance in most situations. The finish retains lubricants to aid in wear resistance and chip flow. 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.