what is trepanning drill?

The broad interpretation of the word “trepanning drill” or “nesting hole” refers to the processing method of machining a hole with an integral core material in the center of an annular groove surface.

Scope of application of trepanning drill:

1. When there are strict tolerance requirements for the diameter, linearity and positional accuracy of through holes larger than about 50 mm in diameter.
2. The depth ranges from about 1.5 times to 160 times the diameter or deeper.
3. Under the condition of workpiece and cutting tool rotation, there is a high metal removal rate.
4. The workpiece material is expensive, and its complete core surplus is much more valuable than chips.
5. The power of the machine tool is insufficient, and holes with larger diameter need to be drilled.

The latest classification of trepanning dril (nesting drills):

According to the different ways of chip removal, it can be divided into internal chip removal and external chip removal.

According to the structure, it can be divided into single-tooth  trepanning  drill and multi-tooth trepanning drill.

According to the different types of cutting tools, it can be divided into BTA type and gun drill type (suitable for removing weight and retaining core below 50mm diameter of small holes).

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