CNC operator machinists oversee the CNC machines that shape parts from metal. Must interpret blueprints, manuals and other work instructions and they also study sample parts to determine dimensions of finished work pieces and CNC equipment setup requirements. They then set the machine and load it with the correct cutting tools. CNC operator machinists inspect work pieces throughout a production run. In addition, machinists measure and mark dimensions and reference points on material or work pieces as a guide for subsequent machining.