Precision Twist QC91GM High Speed Steel Drill Bit Set - 12 Pack, TiN Coated, 5.50mm Diameter, Long Length, Parabolic Flute, 135° Point Angle - Perfect for Metalworking, Woodworking & DIY Projects

The Precision Twist QC91GM taper-length drill bit is a parabolic flute design, 135-degree radius, split-point, round shank drill bit made of HSS with a TiN finish. It is suitable for drilling to a depth up to six 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 with best performance in steel, cast iron, copper, and aluminum magnesium. The QC91GM series has a wide land parabolic flute design that enhances chip (also called swarf) formation and evacuation. Coolant has a better flow to the drill point for heat dissipation, and can be used at higher speeds and feeds for increased productivity. It is recommended to use a constant heavy feed rate while drilling. This design has a reinforced web which provides increased drill strength and rigidity, and straighter closer tolerance holes. Titanium nitride (TiN) is a gold-colored ceramic coating that combines hardness and low friction to extend cutting tool life and permits faster cutting speeds than with uncoated tools. Good for use on items made of alloy steel, carbon steel, plastic, and aluminum. The finish helps increase chip flow in soft materials. 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 340 (metric sizing) industry standards, which ensures 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.