Common types of turning machining techniques: applications, materials, advantages, and how to choose

CNC lathes can perform a variety of machining operations to achieve specific part features. The types of turning operations vary depending on the type of cutting tools and equipment. These processes follow different procedures to meet design specifications, and each operation can achieve different results for different projects. Therefore, understanding the different types of turning processes is helpful in sourcing high-quality custom parts. This article will explore the different types of turning processes, their applications, advantages, and how to choose the right one.

Basic operating procedures involved in turning

Turning is a machining process used to manufacture cylindrical parts, in which a cutting tool moves along a straight path while the workpiece rotates. This process is typically performed on a lathe, a machine tool that holds the workpiece in place of a fixed cutting tool and rotates it. The basic steps of a turning operation are as follows:

Design and CAD Modeling	The first step is to digitally design the parts . Engineers use CAD software to create part models, including all specifications, dimensions, and geometric features. The CAD files will serve as blueprints for subsequent machining.
Material and tool selection	Material selection depends on application requirements, such as strength, toughness, corrosion resistance, and heat resistance. Appropriate cutting tools (lathe tools, drills, finishing tools, etc.) must also be used to ensure efficient cutting.
Machine preparation and tool setting	The CAD file is imported into the CNC system, generating machine-readable code. The technician reliably clamps the workpiece in the chuck, calibrates and aligns the tool, and ensures accurate geometry and compensation settings, which is crucial for guaranteeing high precision.
Processing	The lathe rotates the workpiece at a set speed, and the cutting tool removes material according to the interpolation path of each axis, realizing the CAD design. Cutting fluid is often used during machining to reduce heat and friction, and to avoid affecting the dimensions and surface quality.
Post-processing	After machining, parts can undergo surface treatments such as deburring and polishing, and their dimensions can be rechecked to meet specifications. The typical dimensional accuracy of CNC-machined parts can reach ±0.005 inches, supporting stable and consistent mass production.
Quality control and inspection	Dimensions and tolerances are verified using instruments such as vernier calipers, micrometers, and coordinate measuring machines (CMMs) to ensure that parts meet usage requirements.

Basic operation types of turning

Turning can involve a variety of different operations, depending on the desired effect. This process can be either internal or external machining. External machining is used for the outer diameter of the workpiece, while internal machining is used for the inner diameter.

External turning

Turning	This operation can be either roughing or finishing. In roughing, the final part has a precise rough surface finish. Finishing produces a fine and glossy final part. Furthermore, surface features can range from steps and tapers to chamfers and contours.
Hard turning	Hard turning is similar to regular CNC turning and is primarily used for hardened steels with a hardness range of 58 Rc to 68 Rc. Hard turning is an alternative to CNC grinding. Compared to grinding, hard turning is more efficient, faster, and more cost-effective.
face	Face turning aims to reduce the length of a part. In face turning, the end of the workpiece is perpendicular to the axis of rotation and moves relative to the tool. This process makes the part smooth.
Grooving	Grooving involves creating narrow cuts in a workpiece. The dimensions of the cut are related to the width of the cutting tool. The wider the tool, the larger the groove that can be machined. Very large grooves require multiple passes and longer processing times. The groove can be located on the outside or surface of the workpiece.
Farewell	During cutting, the cutting tool moves radially to the side of the workpiece. When it reaches the inner diameter or core, it separates or cuts off a portion of the raw material.

Internal turning

Boring	Boring involves rotating a pre-drilled workpiece on an insert. Boring operations help to enlarge smaller holes, straighten holes, and cover die-casting defects .
Drilling	Drilling uses a drill bit to create holes in a workpiece by slowly removing excess material. The size of the drilling tool determines the diameter of the hole.
Tapping	Specialized tapping tools with indexable inserts that move axially along the side of the workpiece are used. These tools have a 60-degree angle and can cut threads on the outer surface. Thread lengths vary, and some threads may require multiple passes.
Knurling	The knurling process on a CNC lathe creates patterned ridges on a metal workpiece. These serrated patterns enhance grip.
Enlarged hole	Reaming uses specialized tools to enlarge pre-drilled holes and improve their surface finish. It is similar to boring and drilling. It is primarily used as a post-processing technique.

The most common type of CNC lathe on the market

CNC lathes come in various types, each designed to handle specific machining tasks and applications. The following are the most common types:

Horizontal CNC lathe

These are the most widely used CNC lathes, designed specifically for cylindrical workpieces. They are ideal for turning operations such as cutting, drilling, and threading.

Vertical CNC lathe

Vertical lathes fix the workpiece on a vertical axis, making them suitable for large, heavy parts that are difficult to install horizontally.

CNC turning center

Turning centers are more advanced than standard CNC lathes, offering more functionality. These advanced machines can perform more complex machining operations, including milling and drilling, without the need for auxiliary machine tools.

Swiss-type CNC lathe

These lathes are specifically designed for high-precision work and are typically used to produce complex, small parts. They feature a sliding headstock that provides excellent support for slender parts.

Multi-spindle CNC lathe

These machines are designed for high-volume production of customized, complex parts and can process multiple workpieces simultaneously, significantly increasing productivity. They are typically used in high-volume production environments.

Vertical lathe (VTL)

Vertical lathes (VTL) are the primary equipment for processing large and heavy workpieces. VTL are commonly used to machine components such as turbine housings, large valves, and heavy engine parts, and can perform high-quality machining on large workpieces.

How to select the correct turning operation

While CNC turning technology can produce a wide variety of products, choosing the right operation method is crucial for project success. Let’s discuss some key considerations to help you get on the right track.

Material type

Different materials have different machinability. Certain turning operations may weaken the strength of the workpiece, depending on the material.

Dimensional accuracy

Each CNC turning operation has a different level of precision. Operations such as turning and facing excel at creating high-precision features such as cylinders and planes. Drilling and knurling may have slightly lower inherent precision due to factors such as drill bit deflection or tool vibration. Therefore, you need to carefully consider the inherent precision and required tolerance level of each operation to select the correct one.

Surface treatment

Compared to drilling or knurling, turning and facing typically produce smoother surfaces. Furthermore, operations such as reaming and polishing are specifically designed to improve surface finish after initial machining. Understanding the impact of desired surface finish on the functionality and aesthetics of a part will help you choose the most appropriate CNC turning operation.

Shape and features

Turning can machine cylindrical shapes and simultaneously face flat ends. Threading can produce external threads, while tapping can produce internal threads on screws. Choosing the wrong operation will not achieve the desired results. Understanding the function of each operation and their synergistic effects will help you choose the successful operations.

Advantages of turning technology

In manufacturing, CNC turning is a popular process for mass-producing custom parts because it offers many unique advantages.

Dimensional accuracy

Turned parts meet strict dimensional standards and precise measurement requirements.

Multifunctionality

It can perform a variety of operations and adapt to different materials. Multiple cutting tools and powered rotary tools can machine complex circular geometries.

Mass production

Advanced turning equipment can shorten the mass production time of complex parts and reduce costs.

Material selection

Turning technology is applicable to various metals, plastics, composite materials, carbon fibers, ceramics and other non-metallic materials.

Can complex parts be designed using turning?

Turning is an essential machining operation, highly effective for creating complex shapes with precision and efficiency, and for producing intricate designs. Turning processes are also well-suited for manufacturing parts with tight tolerances and complex contours for various industry applications, where CNC turning can truly shine. Based on real-world project experience at Xtproto, we have incorporated more advanced technologies, such as multi-axis CNC lathes in our workshop. These machines can perform multiple operations simultaneously, reducing setup time and increasing productivity. These machines offer greater versatility, enabling the creation of complex parts on the surface of a single component, such as grooves, undercuts, and multiple diameters, highlighting the capabilities of CNC turning. Furthermore, our engineering team, leveraging CAD/CAM systems, ensures strict adherence to specific designs and the manufacture of correct part features, as the model is directly interpreted by the machine’s motion. Frequent process checks and new methods also significantly contribute to increased turning productivity, producing contemporary, more complex shapes with superior quality and accuracy.

Why trust Xtproto’s guidance? Practical experience from our manufacturing experts.

Theoretical concepts are less relevant in real-world manufacturing projects because any type of guidance must be adapted to the actual manufacturing environment and application. Xtproto’s specialized turning technology covers all aspects of real-world applications, from rapid prototyping to mass production. The information shared here is based on our extensive experience. We have successfully delivered over 50,000 custom parts, drawing on the direct experience of our engineering and manufacturing teams. Our insights will be invaluable when dealing with the most demanding tolerances and application scenarios.

Finally, we’ll apply this practical experience to real-world applications, helping you understand how to select CNC milling materials and avoid costly pitfalls. This will help bridge the gap between data sheets and actual manufacturing results, leading to reliable manufacturing outcomes.

Choosing to collaborate with Xtproto on precision turning projects

Xtproto’s CNC turning services cover a wide range of turning operations, helping you realize your creative ideas. We combine advanced technology with experienced technicians to produce top-notch custom prototypes and production parts. No matter the complexity of the part, our CNC turning expertise ensures precision in the machining of your components. We offer durable components, including planes, slots, radial and axial holes, and grooves, at highly competitive prices. Submit your design files today and start your project.

in conclusion

We offer a wide range of turning machining services and can also use this technology to manufacture complex parts. The versatility of our multi-axis turning equipment allows it to handle various materials and produce diverse shapes. CNC turning, with its precision, efficiency, and versatility, forms the cornerstone of modern manufacturing. This article outlines the turning process, advantages, applications, and equipment types. With the continued advancement of automation and data integration, CNC turning will undoubtedly continue to drive process innovation and performance improvements across various industries.