Common Materials for CNC Machining
One of the most significant advantages of CNC machining is that it is compatible with a wide range of materials. It is essential to select the right CNC material for part design, as it would determine the properties of the final parts. CNC machine can work with almost every material as long as it doesn’t damage the cutting tool. It is possible to perform machining and shapes various materials, including metal, alloys, plastics, composites, fibers, and wood.
This article will discuss the common metal, their alloys, and plastics used in CNC machining projects.
Common Metals and Alloys for CNC Machining
Metal and alloys are used in CNC machining for various applications, from simple machining tools to advanced aircraft and defense parts. They offer mechanical strength, hardness, electrical & heat conductivity, wear & tear resistance, and many more. Metals have high melting and boiling points, so they are flexible with the operating temperature.
Metals can operate at a wide range of temperatures because they have high melting and boiling points. Metal and alloys can be machined using CNC technology as long as their hardness does not result in tool damage. Let’s take a closer look at the common metals and alloys used in CNC machining.
Stainless steel
Stainless Steel
Stainless steel is a steel alloy, where carbon and chromium are the primary alloying materials. However, other elements are also present in specific grades, such as molybdenum & Sulphur. Stainless steel offers High tensile strength, corrosion, and thermal resistance.
It has extensive applications in the construction, automotive, aerospace, defense, heavy machinery, surgical equipment, kitchen appliances, hardware, and tool sectors, among many others. It is used in various applications requiring a high degree of mechanical strength and reliability.
Popular grades of stainless steel for CNC machining are 304, 316, 416, and 17-4 PH.
| Grade | Properties | Applications |
| 303 | The addition of Sulphur in stainless steel improves machinability. Still, it remains tough and austenitic. | Aircraft parts, architectural parts, pumps, valves, nuts, bolts, and many more. |
| 304 | Low carbon grade offers better formability and weldability. | Machinery parts, automotive parts, screws, food handling equipment, and various household applications. |
| 316 | Offers excellent corrosion resistance as compared to other grades. It provides excellent wear and tears resistance. | Aerospace parts, medical and surgical equipment. |
| 416 | High machinability, less corrosion resistance, and more hardness. | Tough parts for different applications, electric motors, nuts, bolts, and many more. |
| 17-4PH | Excellent magnetic properties, high corrosion resistance, | General metal work applications, paper, petrochemical, aerospace, food processing, and medical. |
For property details please check the stainless material properties service, or you can also learn about fabrication projects with stainless steel for a close look at the real application.
Aluminum
The high strength-to-weight ratio of aluminum makes it a popular material for various CNC machining projects. It also has a broad spectrum of mechanical and physical qualities and high machinability. It is super resistant to corrosion and compatible with an extensive range of working temperatures.
Aluminum
Aluminum is used in many applications, from lightweight doors and windows to rocket components. Aluminum alloys are used in automotive, aerospace, construction, medical, defense, home appliances, and many more. Depending upon the particular application, some finishing or post-processing might be required.
Two grades of aluminum alloys are most popular for CNC machining, 6061 and 7075. Learn more about aluminum alloy properties.
| Grade | Properties | Applications |
| 6061 | It contains magnesium and silicon, Excellent corrosion resistance, good formability & weldability, Lower strength than 7075. | Automotive, aircraft, electronics, ship buildings, hardware, sporting products, and many more. |
| 7075 | Alloyed with Zinc, High strength than 6061, Good fatigue strength, and Excellent corrosion resistance. | Different automotive parts include meter shafts, gears, regulating valves, interiors, aircraft, defense, and many more. |
Related:
3003 Aluminum vs. 6061 Aluminum: A Comprehensive Comparison Guide
Copper
Copper
Copper is an excellent CNC machining material that offers outstanding thermal and electrical conductivity, including the shiny reddish brown appeal. It provides superior corrosion resistance, machinability, mechanical strength, and flexibility.
Copper is used in wire& cable applications, electrical appliances, marine hardware, construction, vacuum equipment, and many more.
Two alloys of copper are popular for CNC machining, alloy 101 and alloy 110.
| Grade | Properties | Applications |
| 101 | It is a pure copper alloy with high impact strength, ductility, and excellent electrical & thermal conductivity. It is less corrosion resistive than 110. | Electrical & thermal applications, wire & cables, general engineering applications, |
| 110 | It is less pure and offers a high level of electrical and thermal properties, more corrosion resistive than 101. | Superconductor magnets, jewelry, electrical and thermal applications, hardware, building materials, and many more. |
Related:
Brass
Brass
Brass is a copper alloy that contains a mixture of zinc. Along with strong tensile strength, impact resistance, and shear resistance, brass also offers outstanding machinability properties. It’s a highly well-liked, low-friction, and gold-like material in CNC manufacturing.
Brass has numerous applications in heavy industrial components, musical instruments, automotive, electrical, aerospace, defense, medical, architecture, hardware, and many more sectors.
Related: CNC machining of Brass: Everything you need to know
Brass has two popular alloy grades for CNC machining, C3604, and C3602.
| Grade | Properties | Applications |
| C3604 | Good machinability, high mechanical strength, compatibility with cold and hot pressure processing, and excellent wire and welding properties. | Electronics, hardware, architecture, hardware, and fittings. |
| C3602 | High plasticity, corrosion resistance, good machinability, and strength. | Automotive parts, waterworks, valves, shipbuilding, oil & gas, piping, energy industry, and many more. |
Titanium
Titanium is a rare material with various unique Mechanical and physical characteristics. It offers outstanding corrosion resistance, bio-compatibility, strength-to-weight ratio, and thermal & chemical stability. Although it is a rigid material, it can repeatedly flex in CNC conditions.
Titanium is most popular in the bio-medical industry. It has various automotive, medical, aerospace, and other applications.
In CNC machining, Ti-6AI-4V is the most common alloy grade of titanium, more detail about titanium properties.
| Grade | Properties | Applications |
| 6Ti-6AI-4V | Lightweight, High strength-to-weight ratio, high temperature & corrosion resistance, and bio-compatible | Medical instruments, jewelry, aircraft parts, medical implants, and many more. |
Related:
CNC machining of Titanium & Alloys
CNC Machining: Titanium vs Steel
How To Polish Titanium: Ultimate Guide to Titanium Finishing
Alloy steel
Alloy Steel
Small amounts of iron, carbon, and other substances are used to create alloy steel depending on the desired mechanical and physical properties. Alloy steel is strengthened, structurally stable, and hardened by trace amounts of other components.
Alloy steel is ideal for various applications, including tooling, automotive, defense, and maritime, thanks to its low cost and high strength.
In CNC machining, 4041, 4130, and 4140 are the popular grades of alloy steel.
| Grade | Properties | Applications |
| 4041 | Good mechanical strength & toughness, heat treatable, excellent hardness. Ductility and wear resistance | High-stress applications, shafts, bolts, gears, coupling, piston rods. |
| 4130 (30CrMo in china ) | High strength, hardenability, toughness, and low deformation | Bearings, automotive parts, crushing machinery, drill bit & cutters, and many more. |
| 4140 (structural steel 42CrMo in china) | High toughness, mechanical strength, machinability, fatigue strength, impact resistance, and abrasion resistance. | Shafts, gears, machinery parts, aerospace, oil & gas. |
Common plastics for CNC Machining
The CNC machining process is compatible with various plastic materials, including ABS, Acrylic, Delrin, PPMA, and others. Because of their distinctive physical, mechanical, and chemical properties, plastics are used frequently in CNC machining projects for various applications.
Plastics are a low-cost material with several desirable qualities, including good strength, lightweight, thermal and heat insulation, flame resistance, dimensional stability, machinability, and many others. For various parts and equipment, the automotive, aerospace, electrical, medical, and many more industries rely on plastic machining.
Let’s review some of the plastics frequently used in CNC machining.
Related: For more detail about CNC Machining: Plastic parts please take a look at this article below.
ABS
ABS
Acrylonitrile Butadiene Styrene (ABS) is a widely used thermoplastic in CNC machining projects. It offers high mechanical strength, toughness, chemical inertness, and electrical resistance. It can be readily painted, glued, or welded together.
After CNC machining, It leaves a shiny matte finish. ABS allows the production of strong and durable parts for automotive, electrical, electronics, home appliances, toys, fittings, and food processing.
Nylon
Nylon
Nylon is a strong and durable plastic that offers high strength, rigidity, electrical insulation, thermal stability, wear resistance, chemical inertness, dimensional stability, and plasticity.
Nylon is used in electrical insulating equipment, medical devices, circuit boards, automotive & aerospace parts, and many more applications. It is an excellent alternative to metal.
Acrylic
Acrylic is a transparent thermoplastic with various unique properties, making it suitable for multiple CNC machining projects. It is a lightweight material with excellent chemical resistance, Stiffness, thermo-formability, durability, and aesthetic appeal. In addition, Acrylic is also easy for CNC machining and fabrication.
Acrylic
Acrylic is used in various automotive components, including light tubes, panels, tanks, interior design, billboards, water-proof elements, shoes, tennis rackets, Fiber Optic Cabling, and chemical processing.
Delrin
The low-friction material Delrin is perfect for CNC machining with precise tolerances. It has good dimensional stability, Stiffness, rigidity, durability, chemical inertness, and resistance to impacts and moisture.
Delrin is used in many different applications, such as electric insulation, pumps, bushings, fasteners, automotive, construction, and many more.
Related:
Delrin CNC Machining: Everything You Need to Know
Polyethylene (PE)
Engineering thermoplastic Polyethylene (PE) offers a low mechanical strength and hardness but an excellent impact strength. It is well-recognized for being bendable, electrically insulated, highly thermally stable, and oil & steam resistant.
Polyethylene is a flexible engineering material that works best in various applications, including food processing, medicines, packaging, agricultural products, cables, pipes, and fittings.
| Grade | Properties | Applications |
| ABS | High mechanical strength, toughness, chemical inertness, and electrical resistance. It can be readily painted, glued, or welded together. | Electrical, electronics, home appliances, toys, fittings, and food-processing parts. |
| Nylon | High strength, rigidity, electrical insulation, thermal stability, wear resistance, chemical inertness, dimensional stability, and plasticity. | Electrical insulating equipment, medical devices, circuit boards, automotive & aerospace parts |
| Acrylic | Lightweight material with excellent chemical resistance, Stiffness, thermo-formability, durability, and aesthetic appeal. | Various automotive components, including light tubes, panels, tanks, interior design, billboards, water-proof elements, shoes, tennis rackets, Fiber Optic Cabling, and chemical processing. |
| Delrin | High Stiffness, rigidity, durability, chemical inertness, and resistance to impacts and moisture. | Electric insulation, pumps, bushings, fasteners, automotive, construction, etc. |
| PE | Low mechanical strength and electrically insulated, oil and steam-resistant. | Food processing, medicines, packaging, agricultural products, cables, pipes, and fittings. |
Common plastics used in CNC machining
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To sum up
Several materials are compatible with CNC machining. Different metals, alloys, and plastics can be selected according to the requirement of the particular application. Stainless steel, Alloy steel, Aluminum, Copper, Brass, and Titanium are the most common metal and alloys used in CNC machining. ABS, Nylon, Acrylic, Delrin, and Polyethylene are the most common plastics. Prolean offers 100+ material options for your CNC machining projects. We also provide consultation in the selection process from expert engineers. If you are looking for a trusted and reputable company to handle the transformation of your drawing into a real product, Prolean is one of the best choices.
FAQ’s
What types of materials are compatible with CNC machining?
Different materials, such as wood, metals, polymers, textiles, and composites, are compatible with CNC machines. However, the majority of machining tasks use metal and plastic.
What are the most common metal and alloys used in CNC machining?
The most popular metals in CNC machining include titanium, copper, brass, stainless steel, aluminum, and stainless steel. Materials are chosen based on the desired features and properties.
What distinguishing qualities do metal, alloys, and plastics have?
Depending on the specific metal, metals, and alloys provide mechanical strength, hardness, wear resistance, and electrical & thermal conductivity. However, some specific properties depending on the particular metal. At the same time, plastics have several other features, including strong strength, lightweight, and electrical insulation.
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