CNC milling & turning are two processes in producing precision components in the modern manufacturing. In this post, we will explore the key differences between CNC milling & turning, delve into the specific processes involved, examine the materials used, and highlight the applications of each method in custom parts manufacturing.
What is CNC Milling?
CNC milling Service is a subtractive manufacturing process. It involves the precise removal of material from a solid workpiece using a rotating cutting tool. In this process, the workpiece remains stationary while the cutting tool moves along multiple axes—typically three to five—to create complex shapes and features. The cutting tool rotates at high speeds is the key characteristics of CNC milling.
A complete guide: What is CNC milling?
CNC Milling Process
CNC milling starts with creating a 3D CAD model, which is then converted into G-code instructions for the machine to follow. Once set up, the CNC machine uses cutting tools to shape the material precisely based on the design. The entire process is automated and highly accurate, but attention to material type, tool selection, and setup is key to avoid issues like surface defects or dimensional errors. After machining, some parts may need extra finishing to meet specific tolerance or appearance requirements.
Materials Used in CNC Milling
CNC milling is a versatile manufacturing process that can work with a wide range of materials. The materials should be strength, durability, and thermal resistance. And the materials are ease of cutting.
Here are some of the most common materials utilized in CNC milling:
Metals
- Aluminum
- Stainless Steel
- Steel
- Brass
- Titanium
Plastics
- Acrylonitrile Butadiene Styrene (ABS)
- Polycarbonate (PC)
- Nylon
- Polyoxymethylene (POM)
- Polyetheretherketone (PEEK)
- PTFE (Teflon)
- High-Density Polyethylene(HDPE)
CNC Milling Applications
- Brackets and Housings
- Engine Components
- Turbine Blades
- Structural Parts
- Compressor Casings
What is CNC Turning?
CNC turning service is a subtractive manufacturing process that focuses on the removal of material from a rotating workpiece. This technique is essential in producing cylindrical or conical shapes with high precision and repeatability. At its core, CNC turning involves the continuous rotation of the workpiece while a stationary cutting tool, typically with a single-point edge, removes material to achieve the desired shape and dimensions.
A complete guide: What is CNC Turning?
CNC Turning Process
CNC turning starts with creating a CAD model, which is then converted into G-code through CAM software to guide the lathe’s movements. Once the machine is set up—workpiece secured, cutting tools installed, and coolant ready—the process begins. The workpiece spins while the cutting tool shapes it according to the design. Precision depends on proper setup, tool selection, and stable operation. After turning, finishing steps like polishing or coating may be needed to meet final surface and tolerance requirements.
Materials Used in CNC Turning
Metals
- Aluminum
- Steel
- Brass
- Titanium
- Copper
Plastics
- Acrylic
- Polycarbonate
- Nylon
- Polyoxymethylene (POM)
CNC Turning Applications
- Shafts and Bushings
- Hydraulic Fittings
- Propeller Parts
- Valves
- Pump Parts
- Round shafts
Key Differences Between CNC Milling vs Turning
CNC milling and CNC turning are two fundamental machining processes widely used in manufacturing. Each has its unique characteristics, advantages, and applications. Understanding the key differences between these two processes can help manufacturers choose the right method for their specific needs.
Below is a comparative table highlighting the key distinctions between these two machining techniques.
| Feature | CNC Milling | CNC Turning |
|---|---|---|
| Movement | Rotating cutting tool; stationary workpiece | Rotating workpiece; stationary cutting tool |
| Shapes Produced | Complex shapes and non-rotational designs | Primarily cylindrical and conical shapes |
| Material Compatibility | Works with metals, plastics, and composites | Metals |
| Tooling | Uses multi-point cutting tools for efficient material removal | Utilizes single-point cutting tools for precision |
| Machining Complexity | Capable of intricate designs with detailed features | Simpler setup focused on rotational symmetry |
| Production Speed | Generally slower due to complexity of operations | Typically faster |
| Applications | Aerospace components, automotive parts, medical devices | Cylindrical parts like axles, gears, and fittings |
When to Choose CNC Milling vs Turning?
The decision between CNC milling and CNC turning is influenced by several critical factors that determine the most suitable process for a specific manufacturing project. Here are the key considerations to help guide your choice:
1. Part Geometry
Choose CNC Milling: If your project involves complex shapes or non-symmetrical designs, CNC milling is the preferred option. This process excels at creating intricate geometries, pockets, slots, and curved contours, making it ideal for components that require detailed features.
Opt for CNC Turning: When dealing with rotationally symmetric parts, such as shafts, cylinders, or cones, CNC turning is the better choice. Its design is specifically suited for producing cylindrical shapes efficiently and accurately.
2. Production Volume
High-Volume Production: For projects requiring high-volume production of cylindrical parts, consider using a mill turn CNC machine. This type of machine combines both milling and turning processes, enhancing efficiency and reducing cycle times.
Intricate Designs: If your project involves low to medium production volumes or requires extensive milling due to complex designs, CNC milling may be more appropriate. Although it can be slower and potentially more costly, it delivers the precision needed for detailed features.
3. Material Compatibility
Material Considerations: Both processes can accommodate various materials; however, CNC milling can handle a broader spectrum of materials, including metals, plastics, and composites. In contrast, CNC turning is particularly effective with softer metals and materials that exhibit rotational symmetry.
4. Cost Efficiency
Cost Factors: Generally, CNC turning tends to be more cost-effective for producing simple cylindrical parts in large quantities due to its streamlined setup and fewer tool changes. On the other hand, CNC milling may incur higher tooling costs due to the diverse toolset required for different features.
Working with Zhongde CNC Milling vs Turning
CNC milling and CNC turning are two machining processes that play critical roles in modern manufacturing. Each method offers unique advantages and is suited for specific applications.
For exceptional CNC milling services tailored to your specific needs, Zhongde is your trusted partner. Request a quote today and experience our best-in-class CNC milling and turning capabilities.
FAQs of CNC Turning And Milling
While CNC machining offers precision and repeatability, it requires a higher initial investment and skilled programming. For very simple or one-off tasks, manual machining may be faster and more economical.
Milling machines are best suited for flat or complex geometries but less efficient for fully round or axial parts. They also have limitations on part size and tool reach depending on the machine’s axis configuration.
Turning is highly efficient for cylindrical parts, offering excellent concentricity, faster cycle times, and smoother surface finishes. It's especially ideal for shafts, threads, and other round features.
Standard CNC milling tolerances are typically ±0.005 inches (±0.13 mm), but with tighter controls and precision setups, tolerances as tight as ±0.001 inches (±0.025 mm) can be achieved.
Operators should always wear proper PPE, secure the workpiece and tools correctly, and ensure machine doors are closed during operation. Regular maintenance and program verification are also key to preventing accidents.
Common issues include tool wear, spindle misalignment, coolant failure, and software errors. Regular calibration, proper setup, and preventive maintenance help minimize downtime and ensure consistent output.
