Trepanning: When Core Recovery Matters
I use trepanning when the core material has value. Trepanning cuts an annular groove around a solid core instead of removing all the material as chips. The core is recovered and can be used for another part. The economics make sense in specific situations, and the tooling and setup are different from solid deep hole drilling. When Trepanning Pays Off Trepanning makes the most sense for large diameters in expensive materials. The material savings drive the decision. Drilling a 200 mm hole through 500 mm of titanium solid removes about $8,000 worth of material as chips. Trepanning the same hole recovers a 180 mm diameter core that can be used for a smaller part, saving most of that value. ...