What Are The Differences Between CNC Turning Parts and CNC Milled Parts?

The world of CNC machining has revolutionized the manufacturing industry, providing an efficient means of producing intricate parts with high precision. With a range of services available from metal lathe services to sophisticated live tooling for CNC lathes, the domain of CNC machining is vast and varied. However, while the overarching realm of CNC machining offers numerous possibilities, it’s essential to distinguish between its two primary processes: CNC turning and CNC milling.

By making an informed choice between turning in machining and milling, manufacturers can better meet project requirements, achieve cost savings, and ensure optimal part performance.

Overview of CNC Turning Parts

When we talk about CNC turning, we’re delving into a specific type of machining process that involves a rotating workpiece while a stationary, single-point cutting tool is driven to the piece, shaving off layers to create symmetrical objects. This is the essence of turning in machining.


What is CNC turning?

CNC turning is a subtractive manufacturing process where the material is removed from a rotating workpiece using a cutting tool. This method uses CNC turning machines that are, in essence, automated lathes. These machines provide a mechanism where the lathe parts move in tandem with the input from the computer program, ensuring high precision and consistency in the manufactured parts.


Description of the turning process:

  • Operational Movement: The turning in machining process centers around a rotating workpiece. As this piece spins on its axis, a single-point cutting tool traverses in a linear motion, slicing away material to achieve the desired shape.
  • Equipment Involved: The primary equipment in turning is a lathe or a turning CNC machine. These machines, unlike milling apparatuses, focus on leveraging the rotational movement of the workpiece against a static tool to generate precise cuts.
  • Turning Components: Understanding the lathe parts is fundamental for anyone involved in the turning process. Essential components such as the chuck, spindle, and tailstock play crucial roles in securing and spinning the workpiece, while tools mounted on the tool post execute the cuts.
  • Types of Turning Operations: Beyond the basic external cylindrical cutting, turning can encompass operations like facing, boring, threading, and more. Advanced machines, particularly those with live tooling for CNC lathes, bring added versatility, allowing for operations that combine turning and milling.
  • Materials & Components: CNC turning is highly versatile and caters to a variety of materials, from metals to plastics. Given its precision, companies like Worthy Hardware are able to produce high-quality components that cater to numerous industries.

Overview of CNC Milled Parts

CNC milling stands in contrast to CNC turning, offering a unique set of capabilities and benefits in the world of machining. Unlike the rotating action of turning, milling revolves around a cutting tool moving across the surface of a stationary workpiece to shape it as required.


What is CNC milling?

CNC milling is a machining process where a rotary cutting tool removes material from a stationary workpiece to form the desired shape. It is typically used to create parts with complex contours and profiles, or where holes, slots, and other features are required. With the cutting tool moving in multiple directions, the milled part can have varied geometries. This dynamic technique is leveraged at Worthy Hardware to craft precision parts tailored to clients’ specifications.


Description of the milling process:

  • Operational Movement: In the milling procedure, a rotating multi-point cutting tool moves across a stationary workpiece, removing material to achieve the desired design. The tool’s movement is multidirectional, allowing for intricate paths and detailed patterns.
  • Equipment Involved: The mainstay of milling is the milling machine, which can range from manual to CNC-controlled models. Understanding the parts of a CNC lathe and milling machine is essential, as it encompasses components like the spindle, cutter, table, and more.
  • Types of Milling Operations: Milling is a multifaceted process, with operations like face milling, end milling, and angular milling. The versatility doesn’t end there. With advancements like Swiss screw machining, it’s possible to achieve even more complex and precise components.
  • Materials & Components: CNC milling is adept at handling an array of materials, be it metals, plastics, or even woods. The outcome can range from simple flat surfaces to more complex shapes like gears or molds.
  • Milling Depths and Angles: Precision is key in milling. The depth of the cut, the angle of the tool, and even the speed at which the machine operates can all influence the final product. For those keen on precision, insights into CNC precision machining can offer a deeper understanding.

Key Differences between CNC turning parts and CNC Milled Parts


Machining Process & Equipment Used:

  • CNC Turning:

    • Core Equipment: At the heart of the turning machining process is the lathe, a specialized device crafted to facilitate turning operations. These devices can range from manual setups to more advanced CNC turning machines, like the ones employed by leading manufacturers such as Worthy Hardware.
    • Tooling: The turning process uses a single-point cutting tool that engages with the material being machined. This tool is tailored to carve out specific profiles and depths based on the desired outcome.
    • Workpiece Movement: In turning, the spotlight is on the workpiece. The turning CNC machine anchors the material, causing it to spin or rotate. As it does, the cutting tool, moving linearly, skims off excess material to form the component.


  • CNC Milling:

    • Core Equipment: Milling finds its strength in milling machines. These machines come equipped with a robust table to hold the workpiece in place. Modern milling machines offer precision and efficiency unparalleled by older models.
  • Tooling: In contrast to turning, milling employs a multi-point cutting tool. This tool is adept at cutting across different angles, allowing for a wider range of shapes and profiles.
  • Workpiece Movement: Unlike turning, where the workpiece is the star, in milling, the workpiece remains static. The dynamism comes from the cutting tool, which rotates and maneuvers linearly in multiple directions to sculpt the desired part.


Criteria CNC Turning CNC Milling
Machining Process Material removal using a single-point cutting tool Material removal using a multi-point cutting tool 
Equipment Used Lathe  Milling machine
Tooling Single-point cutting tool Multi-point cutting tool
Workpiece Movement Rotating Stationary


Operational Movement:

  • CNC Turning: In the world of turning in machining, the dance is a simple one. The workpiece rotates, presenting its surface to the stationary cutting tool which moves in a linear path. This dance, when executed correctly, results in symmetrical components that boast a high degree of precision.
  • CNC Milling: Milling’s choreography is a tad more complex. Here, the workpiece remains stationary. The cutting tool, on the other hand, not only rotates but also zips across the workpiece in various directions. This dynamic motion allows for intricate designs, grooves, and patterns, catering to lathe services and designs that demand a higher degree of complexity.


Surface Finish and Tolerances:

  • CNC Turning:

    • Surface Finish: One of the advantages of the turning machining process is its ability to produce parts with a smooth and often mirror-like finish. The consistent, linear motion of the cutting tool against the rotating workpiece ensures that ridges and imperfections are minimized, resulting in a polished outcome. Furthermore, the use of custom lathe work allows for specialized tooling that can enhance this finish even further.
    • Tolerance Levels: Turning, especially when executed on advanced turning CNC machines can achieve incredibly tight tolerances. The precision with which the tool engages the workpiece allows for dimensions to be maintained within microns. For industries or applications where precision is non-negotiable, lathe services such as CNC lathing offer an excellent solution.


  • CNC Milling:

    • Surface Finish: The finish achieved through milling can be incredibly diverse, depending on the tooling and motion used. While it’s possible to get a smooth finish, certain milling operations might leave tool marks or ridges. However, with the right setup and by tapping into high-quality lathe machining near me, it’s achievable to obtain finishes that rival those of turning.
    • Tolerance Levels: Milling, especially with CNC-controlled machines, is no slouch when it comes to precision. While certain complex geometries might challenge the tool’s precision, with the right equipment, such as that found at Worthy Hardware, achieving tight tolerances is feasible. The key lies in understanding the milling process intricacies and optimizing the equipment and tool paths.


Types of Operations:

  • CNC Turning:

    • Facing: A primary operation where the exterior end of the workpiece is cut to produce a flat surface.
    • Boring: This entails enlarging an already existing hole. Done correctly, it results in a smooth internal surface, which is often critical for parts like CNC lathe parts.
    • Parting: Also known as “cutting off”, this operation slices a piece off the workpiece, creating two separate parts.
    • Grooving: As the name suggests, this operation carves grooves into the workpiece. This can be done both internally and externally.


  • CNC Milling:

    • Drilling: While many associate drilling with a separate machine, milling machines are often equipped to drill holes into the workpiece.
    • Contouring: This allows for the creation of intricate and curved geometries on the workpiece’s surface.
    • Gear Cutting: For applications that require the transmission of rotational force, gear cutting on milling machines becomes invaluable.
    • Slotting: Perfect for creating slots or channels in a workpiece, slotting is a standard operation in the milling process.


Complexity and Versatility:

  • CNC Turning:

    • Symmetrical or Round Parts: Turning is the go-to method when it comes to crafting parts that are round or symmetrical. The rotation of the workpiece on the turning CNC machine ensures consistent and even removal of material all around the object. Whether you’re looking for smooth cylinders, rounded edges, or other symmetrical shapes, turning is adept at delivering those outcomes. 


  • CNC Milling:

    • Complex Geometries and Non-round Parts: Milling shines when complexity enters the equation. The multi-directional movement of the milling tool, combined with its ability to approach the workpiece from various angles, makes it ideal for intricate designs, asymmetrical shapes, and unique geometries. This flexibility ensures that for projects demanding non-round parts or those with specialized profiles, milling is often the first choice. Exploring the various lathe services near me will reveal just how versatile milling can be in creating diverse components.


Cost and Time Efficiency:

  • CNC Turning: The direct nature of turning, where a single tool interacts with a rotating piece, often makes it faster and more cost-effective for round or symmetrical parts. The setup time is typically lower, and the consistent engagement of the tool with the material ensures rapid material removal. Furthermore, turning often requires fewer tool changes, enhancing its time efficiency. Thus, when mass-producing cylindrical or rounded components, turning is often more cost-effective.
  • CNC Milling: While the milling process might initially seem more time-consuming due to its intricate tool paths and multi-point cutting process, it can be more cost-effective for complex parts. This is because milling can achieve multiple profiles, grooves, and designs in a single setup. The versatility of milling means fewer operations and setups, which can lead to cost savings in the long run. Especially when producing intricate components, milling might offer better value.

Choosing the Right Process

Deciding between turning and milling is not just about understanding the technicalities of each process; it’s about aligning those processes with the specific needs of your project. Whether you’re an experienced engineer or someone looking for lathe machining near me, considering the following factors will guide you to make an informed decision.


Design Specifications

The very essence of your component, from its geometry to its intricacies, plays a significant role in determining the optimal process. As mentioned, turned parts are often symmetrical, making turning the best choice for such components. Conversely, if your design has intricate details, varying depths, or unique profiles, milling offers the versatility to bring such designs to life.


Volume of Production

For large-scale production, the setup time and speed of operation become paramount. Turning, due to its straightforward process, can often be quicker for high-volume runs of symmetrical parts. On the other hand, milling might be ideal for smaller batches or prototypes because of its adaptability and ability to handle intricate designs.


Material Type

Not all materials behave the same way under different machining processes. Some materials might be more suitable for the consistent and linear motion of turning, while others, especially those prone to chipping, might be better milled.


Tolerance and Finish Requirements

If you’re aiming for a mirror-like finish or need parts that adhere to incredibly tight tolerances, your choice might lean towards turning in machining.


Cost Considerations

Budget constraints are a reality for many projects. When weighing the cost and time efficiency between turning and milling, consider factors like machine setup time, tool wear, operational costs, and the potential need for secondary processes.


Trustworthy Suppliers

Lastly, and crucially, the expertise of your chosen supplier can make all the difference. Working with reputable companies like Worthy Hardware ensures that you not only get high-quality CNC lathe parts but also invaluable guidance on choosing the right process.


Worthy Hardware has demonstrated the incredible innovations achievable through these processes. Their commitment to rapid prototyping and high-quality production underscores the importance of selecting the right technique for the job.

For those still wondering, “what is CNC turning?” or “which lathe services near me are best for my needs?”, the answers lie in understanding your project’s requirements and consulting with experts in the field. It’s not just about choosing between turning and milling; it’s about harnessing the power of CNC machinery to realize your goals with precision, efficiency, and artistry.

FAQ (Frequently Asked Questions)


How does CNC milling differ from CNC turning?

CNC milling utilizes a multi-point cutting tool that moves in multiple directions across a stationary workpiece, carving away material to achieve the desired shape. In contrast, in CNC turning, the workpiece itself rotates, and the cutting tool moves in a linear fashion. The main equipment for milling is a milling machine, while turning employs a lathe.


When should I choose CNC turning over CNC milling?

Choose CNC turning when your project requires symmetrical or round parts, or if you’re prioritizing a smoother surface finish and tighter tolerances. If the design is more intricate or has unique geometries, CNC milling might be the better choice. Always consult with a machining expert to determine the best process for your specific needs.