The capabilities of CNC machining are vast, but they are ultimately defined by the materials from which parts are made. Selecting the right CNC material​ is a foundational step in the design and manufacturing process, influencing everything from functionality and durability to cost and lead time. Manufacturers like JRT Machine typically categorize these materials into metals and plastics, each with distinct sub-families tailored for specific applications. Navigating this landscape is key to a project's success.

Metals for CNC Machining

Metals are chosen for their strength, durability, and conductivity.

• Aluminum:​ Perhaps the most popular CNC material, aluminum is prized for its excellent strength-to-weight ratio, good corrosion resistance, and superb machinability. It is widely used in aerospace frames, automotive parts, heat sinks, and consumer electronics.
• Steel & Stainless Steel:​ These alloys are the go-to for applications requiring high strength, toughness, and wear resistance. Stainless steel adds excellent corrosion resistance, making it suitable for medical instruments, food processing equipment, and marine hardware.
• Titanium:​ This is a high-performance CNC material​ offering an exceptional strength-to-weight ratio, corrosion resistance, and biocompatibility. Its use in aerospace components, medical implants, and racing parts is critical, though it is more challenging and expensive to machine.
• Brass:​Brass CNC machining​ occupies a unique niche. It is not typically chosen for high-strength structural applications but is unparalleled for its machinability. Brass parts are easy to produce with high precision and a superb surface finish. This makes it ideal for decorative components, electrical connectors, valves, and fittings.

Plastics for CNC Machining

Plastics offer advantages like lightweight, corrosion resistance, and electrical insulation.

• ABS:​ A common engineering plastic known for its toughness, impact resistance, and good machinability. It's often used for prototypes, automotive interiors, and electronic housings.
• POM (Acetal):​ Known for its low friction, high stiffness, and dimensional stability, POM is an excellent choice for manufacturing precision parts like gears, bearings, and insulators.
• Nylon (PA):​ Valued for its wear resistance, toughness, and chemical stability, Nylon is used for pulleys, gears, and various mechanical components.
• PEEK:​ A high-performance thermoplastic that can replace metal in some applications. It retains its properties at high temperatures and is used in aerospace, automotive, and medical industries.

Within this diverse material toolbox, brass CNC machining​ stands out for its manufacturing efficiency. While a designer might select aluminum for a lightweight bracket or PEEK for a high-temperature insulator, they would turn to brass for components where fast, cost-effective production of complex, precise geometries is paramount. The ability of brass to be machined quickly with minimal tool wear makes it a highly economical CNC material​ for medium to high-volume production runs. Understanding the strengths and limitations of each material group allows engineers to make informed decisions, ensuring the final part performs flawlessly in its intended environment.