Trepanning vs Solid Drilling: Which Approach Fits Your Job

I choose trepanning when the core material is valuable enough to save. Trepanning is a deep hole drilling method that cuts an annular groove and leaves a solid core. I’ve recovered over $12,000 worth of core material in a single year by trepanning Inconel parts. The core can be recovered and used for another purpose. Solid drilling removes all the material as chips. Here’s when each method makes sense. Trepanning Trepanning uses a cutting head with a hollow center. The head cuts an annular groove around a central core. The core is recovered when the cut is complete. ...

June 11, 2026 · Engineer at the Deep Hole

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. ...

June 11, 2026 · Engineer at the Deep Hole