What Is Precision CNC Machining? For design engineers, R&D teams, and manufacturers that depend on part sourcing, precision CNC machining allows for the creation of complex parts without additional processing. In fact, precision CNC machining often makes it possible for finished parts to be made on a single machine. The machining process removes material and uses a wide range of cutting tools to create the final, and often highly complex, design of a part. The level of precision is enhanced through the use of computer numerical control (CNC), which is used to automate the control of the machining tools.