Computer Numerical Control (CNC) machining is a precise, versatile way of producing complex parts, but material choice is key to success. The process involves whittling away material instead of molding or depositing it and can work with metal, wood, fiberglass, and many other materials, but not every material you can use for a component is well-suited for it. Here’s more about making the right choice plus information on four CNC machining materials you may want to keep on hand for your job.
Choose Your Material
A primary factor to consider in CNC manufacturing is how a part will be used. Using a material that will corrode, for example, could impact longevity in some applications. Government regulations from the FDA or FAA may also dictate material choices. Weight may be an important factor in aerospace or automotive applications while heat resistance could be important in others. Material choice for CNC manufacturing must always keep the project budget in mind too.
Aluminum is easy to machine, has an appealing strength-to-weight ratio, conducts electricity well, and resists corrosion. These are among the reasons that aluminum is used often in CNC-manufactured car and bike parts and recreational items. But saltwater and some chemicals will damage aluminum.
Stainless steel alloys have good strength and resist wear, corrosion and distortion. These materials are used when making bolts, nuts, fittings, gears, and shafts. Carbon steel is less expensive than stainless steel, and it can be stronger too. It machines well, is weldable, and can be heat-treated for hardness, making it perfect for small parts that aren’t likely to be in rust-causing environments.
Strong and corrosion-resistant titanium would be perfect for many CNC-manufactured parts, but it’s too expensive for most budgets. Makers use it mostly for military, aerospace, and high-end industrial applications. Among its disadvantages, it doesn’t conduct electricity well and can’t be polished well. It’s sometimes used in medical devices because it’s biocompatible.
An all-purpose thermoplastic, nylon is a top alternative to metal for CNC manufacturing. It’s strong, stiff, resists impact and chemicals, and can flex and bend. It can also be manipulated with additives to attain additional properties. Nylon is used frequently because it’s cheaper than most durable metals and is widely available.
CNC manufacturing is a smart alternative to molding or hand-crafting products and is used in many industries, but there’s no guidebook for choosing the right material. For the best value, strength, and longevity, you must consider your options and choose the right material for your job.