Type of common drill bit

Commonly used drill bits are twist drill, flat drill, deep hole drill, reaming drill, counterboring and so on several types.

1, twist drill: twist drill is the most widely used hole processing tool. Usually the diameter ranges from 0.25 to 80 mm. It is mainly composed of a working part and a handle. The working part has two spiral grooves, shaped like a twist, hence the name.

2, flat drill: the cutting part of the flat drill is shovel shaped, simple structure, low manufacturing cost, cutting fluid is easily imported into the hole, but the cutting and chip removal performance is poor. The structure of the flat drill has two kinds of integrated and assembled. The integral is mainly used for drilling microholes with a diameter of 0.03 ~ 0.5 mm. The prefabricated flat drill blade is replaceable and can be internally cooled, and is mainly used for drilling large holes with a diameter of 25 to 500 mm.

3, deep hole drilling: deep hole drilling usually refers to the processing of hole depth and aperture ratio of more than 6 holes of the tool. Commonly used are gun drill, BTA deep hole drill, jet drill, DF deep hole drill and so on. Nesting drill is also commonly used for deep hole machining.

4, reaming drill: reaming drill has 3 to 4 cutter teeth, its rigidity is better than twist drill, used to expand the existing hole and improve processing accuracy and finish.

5, the countersink: the countersink has more teeth, and the hole end is processed into the desired shape by forming method, which is used for processing the countersink hole of various countersink screws, or the outer end face of the flat hole.