Titanium’s reputation is built on three properties that gang up on the cutting edge.
Built-up edge (BUE). Titanium is chemically friendly — too friendly. At the wrong speed, the material pressure-welds itself to the cutting edge, micro-weld by micro-weld, until the built-up mass breaks away and takes a piece of the tool with it. Speed selection in titanium is not optimization; it is survival.
Heat that goes nowhere. Titanium’s thermal conductivity is a fraction of steel’s. Cutting heat does not leave with the chip — it concentrates at the tool edge, accelerating wear and inviting the welding described above. Coolant delivery is not a comfort feature here; it is process control.
It bends away from the cut. Low elastic modulus means the workpiece deflects under cutting pressure — thin walls spring, slender shafts walk, and the dimension measured with the load on is not the dimension with the load off. Chatter follows deflection. Fixturing, support, and pass sequencing matter as much as the insert grade.
These behaviors are learned in scrapped parts, over years. We have already paid that tuition.
