Our Slogan:Make One,Made More

How to choose suitable materials for CNC machining?

Regardless of the industry you belong to, choosing the right material is one of the most important components in determining the overall functionality and cost of a part.
CNC machining is one of the most common manufacturing methods used to make parts and products. Computer numerical control (CNC) allows parts to be made using a highly automated process, which offers advantages over many traditional manufacturing methods in terms of speed, productivity, and precision. Choosing the right material for CNC machining can be a daunting task. When selecting a material for a part or product, you should consider a variety of factors, including machinability, price, corrosion resistance, strength, weight, and appearance.
Defining material requirements includes mechanical, thermal, as well as cost and surface finish, considering the environment in which the part will be used and the components it will interact with. Selecting the most appropriate material often requires a compromise between two or more design requirements (for example, mechanical performance and cost).

Common metal and plastic materials used in CNC machining

Common CNC machining metal materials include: aluminum, stainless steel, carbon steel and its alloys, copper and its alloys, titanium, magnesium;
Common CNC machining plastic materials include: acrylic PMMA, polypropylene PP, polyoxymethylene POM, nylon, ABS, ultra-high molecular weight polyethylene UHMWPE, polycarbonate (PC), polyetheretherketone (PEEK), polyvinyl chloride (PVC).

Six factors to consider when selecting CNC machined parts materials

  1. Environmental requirements: Different working environments have different requirements for materials, such as high temperature, low temperature, humidity, corrosion, etc. In high temperature environments, heat-resistant alloys such as Inconel or titanium alloys may be more suitable, while in corrosive environments, stainless steel or nickel-based alloys may be more advantageous.
  2. Physical properties: Physical properties such as density, hardness, strength, and rigidity of materials directly affect the performance of parts. For example, parts that require high strength may choose to use high-strength steel materials, while parts that need to be lightweight may consider using aluminum alloys.
  3. Processing performance: The processing performance of materials will affect the manufacturing process and precision of parts. Some materials may be easier to cut, while others may require more special processing methods. Materials with higher hardness may require more wear-resistant tools.
  4. Thermal conductivity: In some applications that require heat dissipation or heat conduction, thermal conductivity becomes an important consideration. Copper and its alloys generally have good thermal conductivity and are suitable for parts with high thermal conductivity requirements.
  5. Economic factors: The cost of materials is also an important consideration. Special materials with high performance are usually more expensive, while some general materials are more economical. When balancing performance and cost, the choice needs to be made on a case-by-case basis.
  6. Surface treatment options: The surface finish you want your product to achieve largely determines the type of material used for CNC machining. Metals and plastics have different surface treatment options, such as polishing, anodizing, passivation, painting, brushing, powder coating, etc. These surface treatment options not only improve the surface appearance, but also improve the function. It is worth noting that these surface treatments interact with the material in different ways. Before selecting a material, it is best to confirm its ideal surface finish.

How to choose different materials in product design?

When choosing the right material, you should consider the working conditions of the part, temperature, wear, humidity. Whether the physical and mechanical properties such as strength, durability, thermal conductivity, corrosion resistance, insulation, magnetic permeability, etc. can meet the working requirements. What is the dimensional tolerance range and surface finish. Once several potential materials are identified, then compare the cost of the material itself, the material processing method and the processing difficulty, build some prototypes to see how they perform during processing and functional testing, how they meet the requirements of the finished part, and make the best choice to balance quality and cost.

Differences between various grades of metal materials for CNC machining

What are the differences between aluminum grades?

AL2014, AL2017, AL2024 aluminum grades are high-strength alloy series, often used to manufacture high strength-to-weight ratios and excellent fatigue resistance, such as aircraft parts, automotive parts.

AL5052, AL5083 are medium-strength alloy series with excellent cold formability, often used to manufacture sheet metal parts and parts that require forging.

AL6061-T6, AL6063, AL6082 are the most commonly used heat-treated alloy series with good corrosion resistance and weldability, often used to manufacture precision machinery parts, consumer electronics, and construction industry components.

AL7050, AL7075-T6 are the strongest alloys currently on the market, often used to manufacture aircraft parts, bicycle industry, rock climbing parts with very strict strength requirements.

What are the differences between stainless steel grades?

SS301, SS302, SS303, SS304 stainless steel has excellent rust resistance.

SS304 is the most rust-resistant stainless steel. It is often used to make metal plates, food processing equipment, kitchen utensils and housings.

SS316 has higher corrosion resistance than SS304 because it contains molybdenum, making it a popular choice for making ships, medical parts, food processing equipment.

SS420, SS430, SS440C stainless steel is a high carbon martensitic stainless steel. It can be heat treated to obtain high strength, good hardness and wear resistance. It is often used to make aircraft parts, medical parts, blades.

SS630 (17-4PH) is a martensitic precipitation hardening stainless steel that can be obtained by solution heat treatment to obtain higher strength and hardness. It is often used in or petroleum and chemical, papermaking and marine fishery industries. .

2205 duplex stainless steel is one of the most common duplex stainless steel grades. The strength is almost twice that of austenitic stainless steel and is often used in high pressure and highly corrosive environments.

What are the differences between steel materials?

Q235 is a low-carbon steel with high plasticity but low strength. It is widely used in mechanical parts with low performance requirements, such as instrument parts, pins, washers, pipes, joints, etc.

AISI1045 is a medium-carbon steel that can be quenched to HRC42~46. It has good mechanical properties and is often used to manufacture mechanical parts such as shafts, gears, high-strength bolts, etc.

AISI4340 4340 alloy steel has the characteristics of high strength, good toughness, good weldability and machinability. It is often used to manufacture structural parts such as power transmission gears and shafts, aircraft landing gears, etc.

Application of different grades of titanium alloy materials?

Titanium alloy is a high-performance material with the following excellent comprehensive properties.

Ti-6242S, Ti-1100, Ti-40 are widely used in aerospace, automotive and military industries due to their high strength-to-weight ratio, excellent corrosion resistance and fatigue resistance, to manufacture aircraft structural parts, engine parts, valves, connecting rods, landing gears and fasteners. Golf clubs, bicycle frames and tennis rackets.

In addition, due to its biocompatibility, corrosion resistance and low elastic modulus, the risk of implant failure is reduced. 6AL4V (TC4) is widely used in medical implants.

Titanium alloys are used in chemical processing plants due to their excellent corrosion resistance and high temperature resistance. Gr1, Gr2 and Gr3 are often used to manufacture equipment such as heat exchangers and reaction vessels.

What is the difference between copper and copper alloy?

Copper is a soft metal with excellent electrical and thermal conductivity. It is mainly used in electrical appliances, electromagnetic switches, Amphenol connectors, solar energy and chemical industries. Common grades include C11000, C12000, C12200, etc.

Copper alloys are formed by adding different types of alloying elements to copper. The performance of various copper alloys varies greatly due to the different added elements.

Beryllium copper is one of the special copper alloys. It has high strength, conductivity, fatigue resistance, heat resistance, and corrosion resistance. After aging hardening, its tensile strength is almost comparable to that of alloy steel. C17200, as beryllium copper, is often used in mold accessories and other occasions with high comprehensive performance requirements.

Brass is the most used copper alloy. Brass is formed by adding zinc to copper, so brass is much cheaper. Common grades of brass are H59, H62, H65, H68, which have good conductivity, high hardness, corrosion resistance, good mechanical properties and wear resistance, and can be used to manufacture electrical components, precision instruments, ship parts, valves and radiators, etc. In some specific occasions, brass can be used instead of copper after nickel plating to save costs.

Differences and application areas between different types of plastic materials

ABS is the most commonly used material for making ordinary parts. ABS has good impact strength, dimensional stability, electrical properties, chemical resistance,
For making transparent parts, you can choose PMMA (acrylic acid), PC. The transparency is very high after polishing.
To make wear-resistant and high-toughness parts, you can choose HDPE, POM (Delrin), PA or PP.
To make insulating parts, you can choose materials such as G-10 and Bakelite.
To make high-temperature resistant parts, you can choose PPSU, PEEK, PTFE Teflon.

Choosing the right material for your project

In the field of CNC machining, the importance of material selection cannot be ignored. With the continuous advancement of technology and the diversification of industrial needs, the characteristics and applicability of materials have become more diverse. According to specific applications and requirements, choosing the right material can optimize the performance and reliability of parts. In addition to the aforementioned factors, the fatigue resistance, conductivity, and magnetism of the material should also be considered. Factors such as chemical media and radiation that may exist in the environment also need to be taken into account, and close cooperation with engineers, designers, and material professionals is required. The material selection of CNC machining parts is a complex process that requires finding the best balance between multiple factors. With the continuous evolution of technology, more innovative materials will emerge in the future, which will bring more possibilities to all walks of life, and it also requires constantly updated knowledge and practices to adapt to the challenges brought by the ever-changing material requirements.

How to choose an excellent precision parts manufacturer?

Choosing an excellent precision parts manufacturer requires many considerations. Whether the manufacturer has a strict quality management system, rich industry experience and expertise, and uses advanced production equipment and technology. Understand its technical capabilities, quality control processes and supply chain management capabilities, and understand cost transparency and sustainability. Review customer references and case studies, evaluate the manufacturer’s communication capabilities, and pay attention to whether its products meet certification and conformity standards. By considering these aspects, you can choose the right manufacturer and establish a long-term cooperative relationship.

Scroll to Top