CNC turning is a type of CNC machining process. With its high precision, high efficiency and stability, it has been widely used in various industrial fields. Whether it is aerospace, automotive manufacturing, or medical devices and electronic equipment, CNC turning can provide excellent parts processing solutions. In this article, we will explore the definition, advantages, applications, surface treatment processes, etc. of CNC turning services.
What Is CNC Turning?
CNC turning is a precise CNC machining process where a CNC lathe is used to shape materials into cylindrical parts. In this method, a raw material bar is securely clamped into a rotating chuck while a cutting tool moves across its surface, gradually removing material from the external diameter. This process continues until the desired shape is achieved, often creating round components.
CNC Turning Machine Process
The precision CNC turning machine process involves several key steps. First, a raw material bar is inserted and clamped into a rotating chuck. As the chuck spins, the cutting tool is precisely positioned by the machine to cut away excess material from the outer surface. The tool moves linearly while the workpiece rotates, efficiently removing material layer by layer. This process creates highly accurate cylindrical shapes. CNC turning includes two types of operations: rough turning, which removes larger amounts of material quickly, and finish turning, which focuses on achieving finer precision and surface quality.
CNC Turning Process Range
CNC turning encompasses a variety of machining processes, enabling the creation of diverse and precise parts. Key processes include:
-Boring: Precision enlargement of existing holes, ensuring accurate internal dimensions.
-Drilling: Initial hole creation in the workpiece using a drill bit.
-Facing: Flattening the end of the workpiece to achieve a smooth surface and precise length.
-Cutting: Material removal to shape the workpiece as per specifications.
-Reaming: Fine-tuning holes for improved accuracy and surface finish.
-Grooving: Creating narrow channels or grooves in the workpiece.
-Knurling: Forming textured patterns on the surface to enhance grip.
-Parting: Separating the finished part from the raw material.
The Principles of CNC Operation
CNC Turning Design Guidelines
Designing parts for CNC turning requires careful consideration to ensure optimal machining efficiency and part quality.
1.Avoid Long, Slender Structures: Parts with long, thin shapes are prone to deflection during machining, which can result in inaccuracy and poor surface finish.
2.Consider Specifying Surface Roughness: Defining the required surface roughness ahead of time helps achieve the desired finish, especially for functional or aesthetic purposes.
3.Balance Depth and Diameter Ratios: The depth-to-diameter ratio should not be too extreme.
4.Avoid Fragile Shapes that May Deform: Fragile designs can be distorted under the cutting pressure. It’s important to ensure the part has sufficient structural integrity to withstand machining forces.
5.Limit High Length-to-Diameter Ratios: Shapes with high length-to-diameter ratios are difficult to machine accurately. A ratio of 2:1 or 3:1 is considered optimal.
6.Cutting Surface Features: The cutting process in CNC turning results in a surface with fine helical feed marks, created by the rotation of the part and movement of the tool.
7.Cutting Surface Features: The cutting process in CNC turning results in a surface with fine helical feed marks, created by the rotation of the part and movement of the tool.
8.Mass Production of Concentric Shapes or Thread Features: CNC turning is particularly effective for creating concentric shapes and threading, making it ideal for batch production of such features.
Common Part Shapes for CNC Turning Centers
CNC turning centers are versatile machines capable of producing a wide range of part shapes, including:
- Straight cylindrical shapes: Commonly used in shafts and axles for automotive and industrial machinery.
- Tubular shapes:Hollow forms for pipes, medical devices, or structural components.
- Threaded shapes: For bolts, screws, or parts with threaded holes, used in mechanical assemblies.
- Grooved shapes:Ideal for O-rings and sealing components in hydraulic or pneumatic systems.
- Knurled shapes:Found in handles or knobs where grip is important, like in hand tools.
- Chamfered shapes:Edges used for reducing sharpness, common in mechanical fittings.
- Shouldered shapes: Seen in stepped shafts or components requiring multiple diameters for assembly.
- Profiled shapes: Like chess pieces, suitable for decorative objects and custom fasteners.
CNC Turning Maximum Part Sizes
The maximum part size that can be processed by a high quality CNC turning center varies depending on the machine’s capabilities.
Parameter | Typical Maximum Size |
Maximum Diameter | Up to 500 mm (20 inches) |
Maximum Length | Up to 1,000 mm (40 inches) |
Maximum Chuck Size | 250 mm to 400 mm (10 to 16 inches) |
Spindle Maximum Through Hole | 40mm(1.5inches) |
Benefits and limitations of CNC Turning
Benefits
- Smooth Surface Finish:CNC turning can achieve smooth surface finishes, often eliminating the need for additional finishing processes.
- High Accuracy and Precision: It provides exceptional accuracy and precision, ideal for producing consistent, high-quality parts.
- No Need for Complex Tooling: For complex prototypes and small-batch production, CNC turning doesn’t require complex tooling, saving time and costs.
- Low Setup and Machining Costs: With fast setup and processing, CNC turning offers low costs and quick turnaround times.
- Material Versatility: A wide variety of materials can be machined, including metals and plastics, making it highly versatile.
Limitations
- Shape Restrictions:CNC turning is primarily suited for cylindrical or symmetrical shapes and cannot easily produce rectangular or highly irregular parts.
Secondary Surface Finishing Processes
Process | Description | Application |
Polishing | Smooths and shines the surface by removing fine scratches | Used for decorative or aesthetic parts, such as jewelry |
Anodizing | Electrochemical process that adds a protective oxide layer to metals | Common for aluminum parts to improve corrosion resistance |
Electroplating | Coating a metal part with another metal layer, like chrome or nickel | Applied in automotive and aerospace for durability |
Powder Coating | Spraying a dry powder and curing it to form a protective, colorful coating | Used in appliances, furniture, and outdoor equipment |
Sandblasting | Blasting the surface with abrasive particles to create a matte or rough finish | Used for cleaning or creating a textured surface before painting |
Grinding | Precise removal of material to improve surface finish and dimensional accuracy | Applied in high-precision components like bearings or gears |
Available Materials for CNC Turning
Metals Turned Parts
CNC turning can handle a variety of metals, making it versatile for different industries. Here’s a list of commonly used metals:
Material | Types |
Aluminum | 2024, MIC6, 5052, 6061-T6, 7075-T6 |
Stainless Steel | 301, 303, 316L, 17-4, 416 |
Titanium | 6AL-4V |
Magnesium | Various alloys |
Brass | C360 |
Copper | C110 |
Steel Alloys | 4140, 4340 |
Plastics Turned Parts
CNC turning also works well with hard plastics, which are commonly used in prototyping and low-volume production:
Material | Common Types |
Nylon | Various types |
Polycarbonate (PC) | Durable, impact-resistant |
ABS | Common in consumer and industrial applications |
POM (Delrin) | High stiffness and low friction |
Polypropylene (PP) | Chemical-resistant, used in automotive and packaging industries |
PMMA (Acrylic) | Used for transparency and optical properties |
PTFE (Teflon) | High chemical and heat resistance |
PEI (Ultem) | High strength and heat resistance, used in medical and aerospace |
PEEK | High-performance plastic, resistant to chemicals and high temperatures |
What Is Differences Between CNC Milling and CNC Turning？
CNC Turning
- Faster and More Economical:Ideal for producing cylindrical parts quickly and at a lower cost, especially in large quantities.
- Higher Material Waste: Turning typically involves removing more material from the workpiece, leading to less efficient material use and increased waste.
- Surface Finish: Typically achieves a smoother surface finish due to continuous contact between the cutting tool and the rotating workpiece.
- Tool Complexity:Generally uses simpler tooling, reducing setup times and costs.
CNC Milling
- Greater Material Efficiency:Milling conserves material better by only removing what’s necessary, reducing waste and saving on material costs.
- Versatility in Shape:CNC milling excels in creating complex, non-cylindrical shapes, such as rectangular or irregular geometries, making it suitable for a broader range of parts.
- Multi-Axis Capabilities:Allows for machining from multiple angles, which is useful for parts with complex contours and designs.
CNC Turning Applications
CNC turning is widely used across various industries due to its ability to produce precise and complex parts efficiently.
Transportation
CNC turning ensures high precision and durability in transportation systems, for example in manufacturing components such as shafts, bushings and pulleys.
Construction
Essential for producing strong and reliable parts such as fasteners, anchors, and brackets used in heavy machinery and structural elements.
Vehicles
Used in the automotive sector for creating threaded parts, engine components, and other high-precision parts that enhance vehicle performance.
Aerospace Fittings
Manufacturing of specialized fittings, connectors, and other critical parts that require exact specifications and superior material strength.
Threaded Parts
CNC turning excels in producing screws, bolts, and nuts with precise threading.
Valves and couplings
CNC turning can create components that control system flow and pressure.
Factors to Consider When Selecting CNC Turning Services
- Size and Shape of the Parts: The dimensions and geometry of theturned parts being produced impact the type of CNC machine and tooling required.
- Quantity of Parts: The production volume, whether it’s for prototyping or mass production, affects the cost, lead time, and process efficiency.
- Material Type: Different materials, such as metals or plastics, require specific cutting tools, speeds, and processes for optimal results.
- Complexity of Each Component:The intricacy of the design, including features like grooves, threads, and fine details, influences machine setup and processing time.
- Tolerance Specifications:Tight tolerances demand precision machining and quality control measures to ensure parts meet exact specifications.
CNC Turning Services at EASIAHOME
If your business needs CNC turning services, EASIAHOME is your best choice. We have the best equipment, technicians and support staff to deliver high-quality products quickly. If you need, please contact us to get your CNC turning quote.
Frequently Asked Questions (FAQs)
Q: What Is The Horizontal Lathe Anatomy?
A: Headstock Assembly，Chuck，Jaws ，Bed (slant)，Ways Z-Axis ，Ways X-Axis，Tailstock，Index Drive ，Multi-Tool Turret，Cutting Tool
Q: What Types of Materials can EASIAHOME Process?
A: Large castings, forgings, weldments, pipes and bars
Q: What Is The Maximum Size That EASIAHOME can Process? What Is The Minimum Size?
A: Maximum Size: 1600 mm x 1200 mm x 900 mm
Minimum Size: 0.5 mm
Q:What Are the CNC turning Tolerances?
A: Our precision CNC lathes machine to tolerances of +/- 0.01mm; Surface finishes range from Ra 0.8 to Ra1.6.
Q: What Types of Turning Design Files are Acceptable to EASIAHOME?
We accept 3D CAD files in STL, STP, STEP, OBJ IGS or IGES formats and 2D drawings (jpg, png, gif, bmp, pdf) with dimensional details and specific manufacturing requirements.
