The material that fights back
PEEK (polyetheretherketone) is a high-performance semi-crystalline thermoplastic. It survives 260 °C continuous service, resists nearly every chemical, and is radiolucent and biocompatible — which is exactly why semiconductor, medical and aerospace engineers specify it. But those same properties make it awkward on a CNC mill. In short: PEEK is soft, springy, heat-sensitive, and abrasive once filled. Get any one of those wrong and you get burrs, dimensional drift, melted surfaces, or a tool that dies in minutes. The rest of this guide walks through the five failure modes we see most often and the process controls that beat them.