This document discusses high speed machining (HSM). [1] HSM involves machining at spindle speeds above 15k RPM, requiring rigidity throughout the machine and thermal/feedback controls. [2] HSM allows finishing hardened materials and is now more common, having traditionally focused on dies/molds. [3] Compared to traditional machining, HSM uses advanced CAM toolpaths to dramatically increase parameters and reduce tooling wear, improving cycle times and profits.