The main materials used in CNC turning include stainless steel, carbon steel, aluminum alloys, copper alloys (such as CZ119 leaded brass), titanium alloys, and engineering plastics, suitable for a wide range of machining needs from precision parts to large structural components.
Stainless Steel: Common grades include 304, 303, and 316L. It possesses excellent corrosion resistance and strength, and is widely used in the machining of parts for medical devices, food machinery, and chemical equipment. 303, containing sulfur, is easily machinable and suitable for high-precision threaded parts; 316L is mostly used for implants with high biocompatibility requirements.
Carbon Steel and Alloy Steel: Including medium carbon steels such as 45# steel and S45C, suitable for mechanical structural parts such as shafts and gears. High alloy steels, such as mold steel, are difficult to machine and require wear-resistant cutting tools.
Aluminum Alloys: Represented by 6061 and 7075, they have low density and good thermal conductivity, making them the preferred lightweight material for aerospace and consumer electronics (such as mobile phone casings). Due to their strong tendency to stick to the cutting tool, diamond-coated tools are often used for high-speed cutting.
Titanium alloys and high-temperature alloys (HRSA) such as TC4 titanium alloy and Inconel nickel-based alloys. These have high strength and high temperature resistance, but poor thermal conductivity and severe work hardening, making them difficult-to-machine materials. Ceramic or CBN tools are required, and cutting heat must be controlled.
Non-metallic and Composite Materials
Engineering Plastics: Such as POM (polyoxymethylene), nylon, bakelite, etc., used for insulation parts, gears, and lightly loaded structural parts. Melting and sticking to the cutting tool must be prevented during cutting.
Composite Materials: Including carbon fiber reinforced resin (CFRP), glass fiber aluminum, etc., mostly used for high-end aerospace structural parts. They are prone to delamination during machining and require specialized sharp cutting tools.
