Trepanning Basics
Trepanning is a type of boring. An annular cut is made into solid materials in which a solid cylinder or plug is coincidentally made. Another way of saying it is, it is a process of deep hole drilling.
The drilling can leave a core for production of other parts or be used for material analysis. This process requires lesser machine power than any drilling method. It can be very cost effective when drilling bores large in diameter or expensive materials. Trepanning is used for metal industries and the most widely used.
The cutting tool used in trepanning can produce a core or slug, which is a piece that is shaped like a disc, because of the hole it makes in using flat plates. The discs can range up to six inches in diameter and be made from a flat plate or sheet. When the hole is produced, it does not reduce the material like drilling does to chips. It feeds axially not radially and can be considered more of a grooving tool.
The machines used for trepanning can be drill presses, lathes, milling machines and others with either single or multi point tools. The operation for trepanning is considered roughing. There has to be finishing work involved. Which this will involve a second step using boring bars or reamers to finish and adjust the size.
The reasons why trepanning has its advantages: scrap value increases, higher productivity, faster drilling time, and it is cost effective.