A countersink bit is a metal cutting tool designed to improve surface smoothness and hole accuracy. Processing a hole with a countersink bit is countersinking and it allows you:
– to achieve high quality standards;
– to remove out-of-roundness, tapering and other defects;
According to fixation, countersink bits are divided into the following groups:
– shank-type (with a cylindrical or conical shank);
By design, countersink bits are classified as the following:
– solid ones. They look similar to drill bits, that’s why they are sometimes called countersink drill bits. The difference is in the presence of a larger number of spiral grooves and cutting edges (3-6 teeth). As a rule, they are made of high-speed steel with carbide inserts.
– National teams.
Choice of a countersink bit
The correct selection of a metal cutting tool for countersinking is a very important stage, so you must pay attention to the following points:
– The type of tool is selected depending on the processed material, the nature of the treatment. The location of the hole must also be considered.
– The size of the tool for countersinking is selected based on depth, diameter and required accuracy of the hole itself.
– The design of the core drill is selected depending on the method of mounting the core drill on the machine or in the tool.
– The material of the countersink bit depends on the material being processed (there are countersink bits for wood), the intensity of the operating mode and other factors.
Countersinking is a much more productive process than cutting. The cutting speed for a high-speed steel countersink bit is close to the drilling process, however, feed rate is 2.5–3 times higher. That’s why countersinking is faster than drilling.