CNC Machining Materials: Choosing the Right Materials for CNC Machining Project

CNC Precision Machining Lathe Machining Metal Parts, Yong Lihao Machinery's Cnc Manufacturing Capabilities for Multiple Materials

CNC machining is a highly accurate, flexible, and efficient machining process. It is capable of producing complex parts with tight tolerances. Compared with traditional manual machining. CNC machining has a higher degree of automation. It allows the machining of many materials. These include metals like aluminum and stainless steel, as well as plastics and composites. In this article, Yonglihao Machinery explains the process, material compatibility, and applications in detail. Helping you make the most informed choices for your future parts processing.

Table of Contents

CNC Machining Processes

In modern manufacturing, CNC machining offers three main processes: CNC milling, turning, and 5-axis CNC machining. Each process uses a computerized CNC system to turn raw materials into products. But, they differ in machinery, application, and best product type. Here’s a breakdown of the specifics we’ve compiled:

CNC Milling: CNC milling is like drilling and cutting. But, it can move along different axes. This lets it make a variety of shapes, slots, holes, and details in a workpiece. Milling machines can machine many materials, from plastics to metals. They are very versatile for machining parts with complex shapes. The milling method chosen depends on the need for cutting accuracy. It also depends on the complexity of the part design.

CNC Turning: CNC turning involves rotating the workpiece. The cutting tool moves straight. This process is ideal for machining parts with cylinders. It is used for shafts and knobs. Turning (or lathe) machines are great at making parts quickly. They do this better than milling, especially for parts with simpler shapes.

5-Axis CNC Machining: 5-axis CNC machining offers high precision and flexibility. Unlike 3-axis machines, 5-axis machines can rotate in two more axes. This allows the cutting tool to approach the part from almost any direction. This feature reduces the need for multiple setups. It cuts errors and saves time. Five-axis machining is critical for complex aerospace and automotive parts. They need multi-dimensional features and tight tolerances.

CNC milling machine in action - Yonglihao Machinery's advanced cutting and forming processes

Material Selection for CNC Machining

Choosing the right material is critical in CNC machining. It greatly affects the function, durability, and cost of parts. The process involves evaluating the part requirements. It considers the environmental factors the product will face. It combines these factors with budget limits to pick the best material.

Metals: Metals like aluminum, stainless steel, and titanium are favored for their strength, durability, and heat resistance. This makes them ideal for aerospace, automotive, and medical uses. Aluminum is lightweight. It is also easy to machine. This reduces manufacturing time and costs.

Plastics: Plastics, like ABS, nylon, and PEEK, offer unique advantages. They are corrosion-resistant, light, and flexible. Plastics are cheaper than metals. They are used in consumer electronics, automotive parts, and prototypes. These parts need complex shapes.

Composites: Composites are engineered materials. They are made from two or more components with very different properties. In CNC machining, composites can offer specific properties. These include higher strength-to-weight ratios, corrosion resistance, and thermal stability. These are for specialized areas like aerospace and high-performance automotive engineering.

Close-up of a high-speed CNC milling machine spraying coolant

In-depth Analysis of CNC Machining Materials

Yonglihao Machinery recommends careful consideration when choosing materials for CNC machining. Consider their properties and applications. This is to ensure the final product meets all needed specs and quality standards. The next sections describe common metals and plastics used in CNC machining. They also cover unique materials like copper and brass. The emphasis is on their specific uses.

Metals

Aluminum

Aluminum is an easily formed metal that can be used for many different purposes. In addition, it is a widely used CNC material. In general, it is a better choice than metals such as titanium and steel. Aluminum and its alloys are among the most widely used elements. This is because aluminum metal is strong, lightweight, corrosion-resistant, and has a silvery appearance.

However, not every type of aluminum is suitable for manufacturing CNC-machined parts and components. Aluminum 6061 and 7075 are the strongest aluminum alloys. Their high machinability makes them ideal CNC machining materials for making low-weight machined parts. Examples include aerospace frames, aircraft components, and automotive engine parts.

In addition, Aluminum 7075 can be strengthened to T6. 7075 T6 Aluminum is used to make plastic injection molds, automotive and aircraft components, and rugged mountaineering equipment. On the other hand, most machinable aluminum materials are used in healthcare, consumer electronics, architecture, and design.

Carbon Steel and its Alloys

Carbon steel and its alloys offer high machinability and excellent strength. This makes them ideal for a wide range of applications. Carbon steels can function well through various heat treatment methods. As a result, they have better mechanical properties. Carbon steels are usually less expensive compared to most CNC metals. Medium carbon steels are strong and suitable for heavy-duty applications such as rods, bolts, and studs.

Because of its bland appearance, carbon steel is not suitable for projects where appearance is important. Additionally, carbon steel is like mild steel in that they are not a corrosion-resistant material for CNC machining. While alloy steel is better at resisting rust and is more flexible than carbon steel, carbon steel is stronger.

While these materials have their limitations, they still excel in many industrial and manufacturing applications. Because carbon steel and its alloys have better strength, they are easier to machine. Therefore, they are commonly used in CNC machining for structural parts such as beams and mechanical fixtures.

Copper and its Alloys

Copper and its alloys are commonly used in CNC machining because they have strong electrical and thermal conductivity. Because copper has very good electrical conductivity. So it is ideal for manufacturing electrical and computer parts. In addition, copper metal is an excellent CNC material for jewelry making because it looks beautiful. Copper is also commonly used to manufacture wires, metals, and magnetic devices.

Brass, bronze, and copper are indispensable materials for CNC machining. Brass and bronze are common types of metal made from copper and each has its own characteristics. Made from copper and zinc, brass is a soft metal that can be machined and molded without the use of any lubrication. It has excellent electrical conductivity, corrosion resistance, and workability. Manufacturers typically use brass for items that don’t require much strength. Such as small screws, electrical equipment, everyday items, and plumbing tools.

On the other hand, bronze includes copper, tin, and other composite elements. It is tough, durable, and resistant to rust. In addition, bronze is also easy to work with, making it ideal for making precision parts such as bearings and gears. Adding aluminum and phosphorus can make bronze more impact-resistant, tougher, and stronger.

Stainless Steel

Stainless steel is a popular CNC metal with a lustrous appearance. It is very strong, tough, and resistant to rust and wear. Alloy steel is inexpensive and comes in a variety of sizes. However, it is very hard and is one of the most difficult materials to work with in CNC machining. In addition, stainless steel contains chromium, which helps protect against rust.

316 stainless steel is a common type of stainless steel. It has good heat and corrosion resistance. For this reason, it is commonly used in the manufacture of medical tools, outdoor cases, and boat parts. 303, 304, and 316 stainless steel are other common grades of stainless steel used in CNC machining for fasteners such as bushings, screws, and bolts.

However, manufacturers often add sulfur to 303 stainless steel to make it easier to machine. 303 stainless steel is suitable for nuts, bolts, shafts, gears, and fittings. 304 stainless steel is easy to machine and can be welded. It is well suited for kitchen tools, knives, architectural designs, and automotive parts.

Magnesium

Magnesium is a strong, lightweight metal that is easy to use in CNC machining. Because of its excellent heat resistance, magnesium is ideal for high-temperature components such as engines. In addition, magnesium’s light weight helps create cars that are both lightweight and fuel efficient.

Compared to metals such as aluminum, magnesium is less weather-resistant. Magnesium processing is prone to fires and is more expensive to handle. In addition, manufacturers often anodize magnesium parts to improve their resistance to rust.

Titanium

This metal is strong and lightweight, providing a good balance between strength and weight. Titanium is resistant to corrosion, conducts heat, and is compatible with the human body. It is therefore suitable for the manufacture of components in the medical field. In addition, titanium can be welded, surface-treated, and coated. This gives it a more attractive and protective appearance. Although titanium does not conduct electricity well, it has good thermal conductivity and a high melting point.

Titanium is ideally suited for the manufacture of high-quality mechanical parts used in medicine, the military, airplanes, and automobiles. In addition, titanium is particularly suitable for the manufacture of cutting tools for CNC machine tools.

Metal parts machining services offered by Yonglihao Machinery

Plastics

Acrylic Fibers

Acrylic plastics, also known as PMMA (polymethylmethacrylate), offer the advantages of high strength and a clear appearance. PMMA is a good alternative to glass because it is both strong and transparent. This CNC-machined material is versatile because it helps create accurate and high-quality parts.

Although PMMA is prone to cracking and softening with heat, its flexibility and ease of use make it a common choice for CNC machining projects. PMMA is commonly used in the manufacture of displays, lenses, food storage containers, lamps, and clear covers.

ABS

ABS is the most economical plastic with a unique combination of material properties. It includes good processability, tensile strength, chemical resistance, and impact resistance. Product manufacturers often choose ABS as the best material for CNC machining plastic parts. This is because the material is both flexible and economical. In addition, ABS plastic can withstand high temperatures for extended periods of time and is less expensive than many other engineering plastics, such as PEEK.

Additionally, ABS material is best suited for projects where appearance is important because it is easy to change colors. Because it’s easy to change colors, ABS can be used for CNC machining, such as rapid prototyping, protective covers, and automotive parts. In addition to CNC machining, ABS materials are also used for 3D printing and injection molding.

Acetal

Acetal, also known as Delrin or POM, is a strong, flexible plastic used for CNC machining. It is very tough and can withstand impact and moisture. Manufacturers often use Acetal to make precision parts such as valves, gears, and bearings. This is because Acetal-machined parts are very strong and wear-resistant.

Polycarbonate (PC)

Polycarbonate is a material commonly used in CNC machining. It has many useful properties, including being transparent like glass. Because polycarbonate is heat resistant, it does not break easily. This makes it a good choice for high-temperature applications. As a result, polycarbonate is a plastic widely used in CNC machining. It is commonly used in medical devices, computer parts, and automotive parts.

Polyetherketone (PEEK)

Polyetherketone (PEEK) is a strong plastic that can be used for CNC machining. It is characterized by chemical resistance, high strength, and good dimensional stability. This engineering plastic is ideally suited for use in extreme heat or cold conditions. This is because PEEK remains strong even at high temperatures.

PEEK is frequently used by manufacturers of products in a variety of fields, such as food and beverage, aerospace, oil and gas. In addition, it is commonly used to make hinges, pump and valve parts, seals, semiconductor parts, and bearings. This strong plastic material is ideal for manufacturing lightweight equipment. This is because it does not change shape or deform over time.

Polypropylene (PP)

Polypropylene is a flexible plastic used for CNC machining. It is highly resistant to abrasion and can withstand a wide range of chemicals. In addition, polypropylene is a CNC-machined material used in medical applications. On the other hand, polypropylene tends to soften when exposed to heat, which may cause problems during machining.

Polyvinyl Chloride (PVC)

PVC is an affordable CNC machined plastic with good machinability. Its robust structure makes it hard and able to withstand heavy impacts. In addition, PVC materials are suitable for the manufacture of welding chemical tanks, cabinets and benches, valves and pump boxes, fittings, and manifolds.

Nylon

This plastic resin is one of the strongest and most durable materials used in CNC machining. It has high impact strength and is suitable for a wide range of applications. In addition, it has excellent lubricating properties and is available in different types, such as nylon reinforced with glass fibers.

Nylon is a good choice in situations where friction or wear and tear needs to be prevented. Common nylon parts include sliding surfaces, bearings, gears, and sprockets. However, a major drawback of nylon is that it absorbs moisture. Therefore, it is not suitable for use in water.

Plastic parts machining services offered by Yonglihao Machinery

Unique material

People favor copper for its great thermal and electrical conductivity. This makes it ideal for electrical parts, heat sinks, and construction. Copper alloys, like Copper 101 and Copper 110, have different ductility and corrosion resistance. They are used for special applications.

Brass is a mix of copper and zinc. It has the workability of copper but with added strength and corrosion resistance. Brass is popular for decorative items. It’s valued for its looks and conductivity. It’s also used for electrical connectors and musical instruments.

Unique parts machining services such as brass offered by Yonglihao Machinery

Factors Influencing Material Choice

When choosing materials for CNC machining, several factors can greatly impact the decision. They ensure the final product meets specific requirements.

Heat resistance: Materials must withstand high temperatures without degrading. This ability is crucial for applications involving heat. Metals like stainless steel and titanium have excellent heat resistance. They are used in aerospace and automotive components.

Conductivity: For electrically conductive parts, materials with high conductivity, such as copper, are preferred. This property is critical for electrical connectors and heat sinks.

Hardness and surface finish: The hardness of a material affects its machinability and the wear of cutting tools. Hardness and the ability to achieve a smooth surface finish must be balanced. This is needed for both functional and aesthetic reasons. Aluminium and be easily machined smoothly. Harder materials may need special tools.

Summary

Understanding the machining processes, material properties, and their influencing factors is critical. This understanding is key when choosing CNC machining services and materials. CNC milling, turning, and 5-axis machining offer precision and flexibility. The metals and plastics are chosen based on heat resistance, electrical conductivity, hardness, and desired surface finish. Every choice affects the product’s quality and functionality.

Yonglihao Machinery is a top CNC machining service provider. We have the expertise to handle a wide range of materials. We can provide tailor-made solutions for the unique needs of each project.

FAQ

What are the best materials for outdoor applications?

Stainless steel and aluminum are great for outdoor use. They resist corrosion and last a long time.

How can I reduce CNC machining costs?

Choose materials that are easier to machine, like aluminum. Also, design parts with minimal complexity. This will reduce machining time and tool wear.

Tips for achieving the desired finish on machined parts?

Choose a material that can be easily finished. Use proper cutting tools and settings. Also, think about post-processing techniques. For example, consider polishing or anodizing to enhance the surface.

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