Ti-6al-4v

Titanium is the material that separates experienced deep hole drilling shops from the rest. I have drilled more titanium holes than I can count — here is what I have learned about making them consistently. Every titanium alloy behaves differently. Get the parameters wrong on one alloy and you lose the tool, the part, or both. Get them right across the board and titanium becomes predictable. I cover the broader aerospace deep hole drilling landscape in another article. This one is specifically about titanium parameters, tool life, and coolant — the three things that matter most when the material is titanium. ...

I have drilled more titanium deep holes than I care to count, and I learned the hard way that titanium is not “tough steel.” It is a different animal. The thermal conductivity is roughly one-fifth that of steel. The chips are not chips – they are razor-edged bands that carry all the heat out of the cut. The work-hardening rate is aggressive enough to ruin a new gun-drill in seconds if you let the tool rub instead of cut. Every fix I learned on steel had to be re-learned for titanium. This article covers the specific failure modes I encounter in titanium deep hole drilling and the adjustments that actually work. ...