CNC machining can produce parts from a wide range of plastics and metals. Due to the vast array of materials, choosing the suitable material for your product can be cumbersome. For instance, products that require thermal resistance, hardness, and high strength usually use metals. Parts that need electrical insulation and chemical resistance can use light plastics. Selecting an appropriate material for a CNC mold can be challenging, but the burden lessens with information about the different types of CNC materials.
When choosing a machining material, you may need to consider several cosmetic appearances, corrosion resistance, weight, workability and strength. To determine the most compatible material, you may need to prioritize the crucial features for your final product.
You may also need to analyze the cost of the materials and align it with your budget before making the final decision. You can also compare the available materials before deciding on the most suitable one for your product. Below are some of the available CNC materials and their characteristics.
Aluminum 6061 is a general-purpose CNC material that can create a wide range of parts. Its alloying elements, including silicon, iron, and magnesium, make it resistant to corrosion from atmospheric components and give it a reliable strength-to-weight ratio.
Additionally, this material has CNC machinability, can be anodized and welded, and is widely available, making it cost-efficient. One of the downsides of aluminum 6061 is poor corrosion resistance when exposed to chemicals or saltwater. This CNC material is best suited for sporting goods, bicycle frames, auto parts, and specific frames for RC vehicles and aircraft components.
Brass is a unique copper alloy that is suitable for numerous machining applications. It is an indispensable component in manufacturing industries due to its unique characteristics. Brass is an exceptionally soft metal that is often machined without lubricating it. Its workability is also impeccable at room temperature, meaning that it is suitable for parts that don’t need great strength.
There are several types of brass, categorized according to the percentage of zinc. The higher the percentage of zinc, the lower the corrosion resistance. Brass is suitable for cosmetic applications because of its high polish, which can be mistaken for gold. This CNC material is non-magnetic but electrically conductive, and you can easily recycle it.
Additionally, brass is also suitable for applications in potentially explosive surroundings because it does not spark upon collision with another metal. You can weld brass, but joining it with low-temperature processes such as soldering and brazing is advisable.
Another exciting feature of brass is that it has natural antimicrobial and anti-bacterial properties, but its use in regard to this property is still under study. Its characteristics make it suitable for making musical instruments, plumbing fittings, naval hardware, and decorative home hardware.
Aluminum 7075 refers to a high grade of aluminum that contains a higher percentage of zinc. It has impressive strength-to-weight features, making it the strongest aluminum alloy among all the aluminum alloys.
Due to its remarkable strength, this CNC material can easily go back to its original shape after cold-forming. Aluminum 7075 can also be anodized and is machineable. You can harden this material to T6, but it is not suitable for welding, making it less reliable. 7075 is ideal for aerospace and automotive frames and high-strength appliances for mountain climbing.
Stainless steel 303
Stainless steel is a versatile CNC material with several alloys and grades with unique characteristics and properties. This material is austenitic and magnetic, containing several components that give it excellent corrosion resistant and machining properties and free machining features.
Additionally, the sulfur component enhances its machinability even though it mildly reduces corrosion and toughness. 303 may not be a wise choice for bending, and it cannot be heat treated. You can use stainless steel 303 for gears, stainless nuts, shafts and fitting. You should, however, avoid using it for marine-grade fittings.
Stainless steel 304
Stainless steel 303 is the most preferred form of stainless steel, and it is a component of many industrial and consumer products. Its alloys include chromium and nickel, which make it non-magnetic and tough. 304 is also machineable and can be welded, unlike stainless steel 303. Another feature is that it is corrosion resistant in non-chemical environments. It is advisable not to contaminate it with other metals when making very sharp cutting tools. 304 is a suitable material for architecture, automotive trim, cutlery, kitchen accessories, tanks and pipes. It is ideal for kitchen appliances because it does not react with most organic acids.
Having several options to choose from increases your chances of getting the exact material you need. However, the numerous options may make it difficult to find a perfect fit. This dilemma often arises from product development and design. Extensive knowledge about the available CNC machining materials helps in making informed choices.