Based on the use of your project there are vast varieties of materials you can select which are compatible with CNC milling technology. As your project requires the use of CNC machining for production, a bottleneck most people have to deal with is the option of CNC materials for the project. CNC machining offers the ability for part production from almost any metal or plastic. As a result of this wide variety of options, the selection of the right materials becomes quite challenging. In a bid to help you eliminate such challenges, we RapidDone have curated the most comprehensive guide on the material option for you to have a successful customed manufacturing project.
What are CNC Materials?
As the name entails, CNC materials are materials that are compatible with the CNC machining process. In CNC machining there are quite a lot of material properties that make machining processes easy for projects and the project owners. Examples of such properties include machinability, yield strength, tensile stress, hardness, and many more.
When these factors are considered, CNC machining becomes easy to carry out. The next section gives an insight into the important consideration for CNC machining materials selection.
Important Considerations for Selecting CNC Materials
When it comes to consideration of materials, the first thing to do is to prioritize your project requirements. It is important to start this section of your project with the must-haves and carry out your research down to identifiable nice-to-haves. There is a lot of chance that this method will help you narrow your material options to a workable number. This will help you and your team make a more informed choice as far as your project is concerned. The following are the important factors that you may consider in your priority list.
√ Environmental Factor
For a lot of manufactures in the machining space, this should be an absolute top-of-the-list requirement. These factors relating to the environment depend on the use of your part to be produced. These factors include cold or heat resistance, chemical tolerance, UV resistance, flame resistance, and many more. Another application is that your part must be medical or food grade. All these factors are very important and it is dependent on the application of your part. For example, a part intended for medical service must tolerate the harsh chemical sterilization or the high heat extremities of an autoclave.
√ Mechanical Factors
For CNC machining, the strength of the material to be used depends on the application. Interestingly, materials come in varieties of forms. For example, parts required to form a particular use may need to fit in anywhere on a continuum ranging from rigid to flexible. This consideration may involve the consideration of tensile strength, yield strength, comprehensive strength or the material must be able to resist impact. This has to do with the application of such a part. Others include wear resistance and many more.
√ Application Factor
Another important factor to consider when selecting parts material is the end use of the part. For instance, steel and stainless steel are quite suitable for CNC machining but in other considerations, stainless steel is more corrosion resistant to steel. A wrong choice in this situation may adversely affect the longevity of your part. In this consideration, another factor to put in mind is FAA, FDA, and industry-specific regulation.
√ Electrical Factor
This is also another application factor. A part may be required to be an insulator, a conductor, or dissipate static. As a matter of fact, the selection of material will depend on this. And this selection is quite important so that the goal of the project at hand will not be forfeited.
√ Weight Factor
Before you select your materials for the project at hand, the weight of such material is quite important. For example, parts to be used in automotive and aerospace must be light enough. Interestingly, the CNC machining space offers quite a variety of materials that are compatible with these applications. Another consideration here is that manufacturers can decide to keep weight down by considering plastic such as ABS especially when they can sacrifice strength.
√ Budget Factor
In some cases, the cost of materials mostly influences the selection of materials. The goal of every manufacturer is to select materials that minimize expenditure while also maximizing desired material properties and performances. The cost of material is important in a CNC machining project. This is because the process creates a large number of scrap materials behind. For instance, some materials called specialty metals are extremely expensive and may have a major effect on the cost of the materials to be used. Therefore it is required of manufacturers to carefully evaluate their budget before deciding on a CNC material for their projects.
Steps Involved in CNC Material Selection
The following are the basic step to follow when selecting a material for your part;
Step One: Set a Requirement for Your Material
This involves mechanical, thermal, electrical, budget, weight, application, and many more. To get it done, you can also consider the environment of the parts application as well as the components it will interact with for strength determination.
Step Two: Identify Compatible Materials with the Requirement Defined Above
With the material requirement above, make a list of a range of materials that best fit the combination of requirements.
Step 3: Selection of the Most Suitable Out of the List in Step Two
Here from the list of the range of materials, select the best option that fits into the requirements considered varieties of factors. A compromise is usually allowed between two or more parts’ material requirements. This is mostly in the case of mechanical factor, budget factor, and performance factor.
The Common Materials for CNC Machining Process
There are vast varieties of materials ranging from metals to plastic, and to woods that are compatible with the CNC machining process. This shortlist provides you with an insight into the most commonly used materials in CNC machining today.
√ CNC Metal Materials
Aluminum exists in a different form of alloys that offer great strength to weight ratio as well as high conductivity in terms of temperature and electricity. These alloys offer impressive resistance to corrosion and are high machinable. Examples include 1000 to 8000 series of alloys such as 6061, 7075, and many more
Stainless steel and its alloys feature distortion resistance high strength, high corrosion, improved machinability in the case of 303 due to sulfur content, and lots more. Other alloys include 304 stainless steel, which is readily machinable, and highly resistant to corrosion. Note that stainless steel 316 is highly resistant to corrosion in comparison with 303 and 304.
This material is commonly used for the machining process. The carbon steel 1045 is less expensive in comparison with most alloys of stainless steel. It features impressive machinability, weldability, heat treatment ability to achieve varieties of hardness.
Steel exists in different forms of alloys compatible with CNC milling services. In most cases, steel is engineered for excellent machinability while specific material characteristics depend on different alloys. Generally, they are used for high-stress applications. Examples of alloys include and are not limited to 1018, 12L14, 1215, and many more.
Titanium is a unique metal in CNC milling services. This is due to its high melting point making it a preferred choice for many industrial applications. Other properties include resistance to corrosion, salt, water, ductility, and more. Interestingly, it is biocompatible and light-weighted with application in medical implants, jewelry, and aircraft components.
Brass is another CNC material commonly used due to its cost-effectiveness, stability, low coefficient of friction, high corrosion resistance, and many more. The application includes field engineering, steam work, plumbing, musical instrument, and lots more.
As far as CNC milling is concerned, only a few metals offer the electrical conductivity of copper. Aside from this, it is highly resistant to corrosion, with impressive high thermal conductivity. The thermal conductivity of copper makes it easier to draw it into different shapes. Copper is applicable in the automotive and engineering industry.
√ CNC Plastic Materials
PVC is used almost in all industries due to resistance to chemicals, corrosion, and flames. It is highly affordable such that is cost-effective for numerous applications. It is applicable for toy production, gas pipes, water pipes, and many more.
Acrylic is a clear-form material with features including durability, machinability, scratch resistance, and many more. It has different material properties than some metals, wood, or other materials. Acrylic is applicable for the production of parts that requires complex or delicate shapes.
This plastic material is called general-purpose nylon. This is because it is easy to machine with moderate flame resistance properties. Nylon is applicable for insulators, injection molding short-run products, and many more.
PEEK is another plastic material with Excellent machinability. It features superior dimensional strength, resistance to impact which makes it a perfect choice for applications including switches, connectors, test sockets, and lots more.
POM (Delrin) is a grade of plastic that may be preferred for cost-effectiveness, electrical insulation, and many more. It has high machinability, and are applicable for mechanical parts
PTFE (Teflon)is another grade of plastic that is highly machinable and may be preferred for cost-effectiveness, and use in electrical components. It features excellent chemical and heat resistance
Polycarbonate is an excellent thermoplastic with impressive mechanical properties, high accuracy, and repeatability. It also features excellent impact strength and good thermal resistance. It is suitable for outdoor applications and can be optically transparent.
√ Other CNC Materials
Plywood and solid wood are CNC machining materials that feature excellent resistance to wear and tear. Both differ from one another in that plywood offer more dimensional stability.
Foams are mostly used in the CNC machining space for performing a test run of models before carrying out a machining process on more expensive materials. For instance, extruded polyurethane is a type of foam used by newbies for CNC milling practice.
Now that we have fully introduced you to the different CNC materials that you can use for your projects, it is now possible for you to plan out which material will be the best fit for your project. This will help you to minimize cost and maximize the application performance without sacrificing quality. If you want to learn more or you have a quoted project on hand, as the best on-demand CNC machining manufacturer, RapidDone expert engineers are always available to help you out. Contact us today if need.