CNC machines are used on a vast array of materials. Each material has its own optimal set of machining parameters (speeds and feeds) to successfully machine the material. The most common materials are:
1. Metal
Meal is easily the most commonly used material in CNC machining. CNC machines can cut almost any type of metal from free-machining brass to nickel superalloys like Inconel. Metal machining covers a range of applications from injection molds to shafts and gears.
2. Plastic
While the vast majority of plastic parts are manufactured using injection molding, CNC machining may be used to produce certain plastic components. Typical materials can include ABS (acrylonitrile butadiene styrene), nylon, and polycarbonate. Plastic machining applications can include valve bodies, bushings, and injection molding prototypes to check the overall function of the part before investing in expensive molding tools.
3. Wood
CNC routers are most often used to cut wood and are generally cheaper than standard metal cutting CNC machines. CNC machining of wood is most commonly done for decorative purposes. Common applications include furniture, window frames, and ornamental panels.
4. Foam
Polyurethane foam (either closed or open-cell) is commonly used in CNC machining applications. Foam blocks can be cut into snug packaging for high-value products using a CNC router. One example is the foam used in toolboxes to keep the tools secure during transport.
5. Composites
CNC machines are regularly used when processing composite parts. Composites can include anything from aramid to fiberglass to carbon fiber. These materials are extremely abrasive to cutting tools. Aerospace and marine composite components are machined to add fastener holes and for general trimming after the molding process.