Most common types of drill bits

Twist drill bits are some of the most common types of drill bits. They are mainly used for drilling metal, wood, and plastic. Twist drill bits vary in size, from 1/16 of an inch to an inch in diameter. The size can even be larger for commercial applications. For woodworking, twist drill bits are used at very high speed. When drilling in metal, they are tuned much slower to keep them from heating up excessively.

drill bits

Bit Shank

A twist bit shank is the segment that lodges into the drill chuck. The shank is normally smooth and has the same thickness in bits of up to ½ inch in diameter. The shank may shrink or become narrower than the bit breadth on bits larger than ½ inch.


The point of a twist drill bit is ground. It creates two chisel-like cutting edges widening out from the point at the tip’s center. The point is at a steeper angle for wood cutting bits than in metal cutting bits. This makes it possible for the bit to cut more effectively through wood.


Twist drill bits have two or extra flutes and deeply cut grooves that twists upwards from the bit point. The flutes takes the cut material and haul it from the hole being drilled .Flutes are important because without them, the drill bit would be ineffective in removing the cut material.

Drilling Wood and Plastic

The drill bit can be tuned at high speed rates when drilling soft plastic and wood. This makes it easy for the bit to drill through the material faster. No lubrication is needed for softer materials because they do not cause the bit to overheat.

Drilling Metal

The point of the twist drill has to be a little less flat when drilling into metal. The drill should also spin a bit slower than when cutting plastic or wood. This way, the bit will make thin cuts through the metal and prevent the bit from binding. Lubrication can help keep the bit from overheating.

Making the Tip

Drill bits are made from strong steel alloy rods. The rods should have flat ends and cylindrical in shape. The flat ends of the rods must be modified into gently sloping and cone shaped tips. Drill bits play an important role in the application of PVD coatings.

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