Both milling and turning are two distinct machining operations you can use to make different components.
Depending on your machining needs, you can choose either one machining operation or both. However, this is only possible once you have an in-depth knowledge on turning and milling.
What is Turning on Lathe?
In turning, the workpiece rotates around a fixed axis, while the turning tool remains stationary or moves linearly to remove material. In most cases, the end products of turning operations are cylindrical-shaped parts.
What is Milling?
During milling, the turning tool rotates and moves along multiple axes, while the workpiece is typically fixed; however, in advanced multi-axis milling, the workpiece may also move to achieve complex geometries.
For this operation, you will need machining center or CNC milling machine. The movement depends on the complexity of the part, where you can use either 3, 4, or 5 axes.
Differences Between Turning and Milling in Lathe Machines
· Turning Action- During Turning
During turning, the workpiece rotates at a high speed with its main turning-edge removing materials from the workpiece in a controlled manner by shearing.
When milling, the turning tool rotates instead of the workpiece.
· Tooling for Machining
In turning, a single tool with one sharp turning edge is rigidly clamped in the tool holder designed for continuous chip removal.
In most cases, the multi-head tooling systems are clamped in a movable turret or table to offer uninterrupted turning.
· Final Product (Shape of Final Part)
The end products are often rotationally symmetric (cone-shaped or cylindrical-shaped parts).
In milling, the process is versatile, thereby providing different shapes other than cylindrical or conical designs. During milling, you can also achieve complex shapes such as gear teeth, helical grooves, etc.
· Movement of the Workpiece and Tooling
During turning, the workpiece rotates within an axis, while the turning tool is stationary.
During milling, the workpiece stays fixed. The tooling system will rotate at high speed, while also moving in specific axes according to G-code and M-code programs.
· Machining Cost
Turning on a lathe is affordable since it produces cylindrical parts requiring economical tooling, low cycle time, few setups, and a low scrap risk.
On the other hand, milling is more expensive since it has a complex setup. Its tooling wear is higher and has a high scrap risk.
· Type of Machine to Use
In a turning operation, any lathe machine is good for work. The workpiece rotates, and the tool is fixed and moves linearly.
Both 3-axis and 5-axis CNC milling machine make the machining operation fast, efficient and accurate. They have extra-fitted attachments and good capability to handle their complex work.
Apart from the linear turning axes like the x, y, and z, you also get additional rotating axes like the A, B, and C. With multi-head milling machines, you can make diverse parts and components.
· Type of Waste
Turning produces continuous chips that are long or spiral on softer metals and short, broken chips for harder metals.
Milling produces small and broken fragments in irregular shapes. There is a possibility of more dust-like waste from hard materials.
How to Choose Between Turning and Milling
When turning or milling, consider when you want:
| Turning | Milling |
| A smooth cylindrical or conical surface | When you need irregular surfaces or complex shapes. |
| When the workpiece is rotationally symmetric | When the workpiece has flat surfaces, pockets, slots, and keyways. |
| If you want high material removal on round stock | If you want precise cavities and slots |
| A superior concentricity, roundness, and surface finish for cylindrical shapes. | A superior accuracy on flatness, squareness, and geometric complexity. |
| A faster cycle time for shafts and round parts. | A slower for pure round parts |
| Cheaper tooling | Higher tooling cost |
Conclusion
Turning and milling machining processes differ in many ways. However, together they expand the capability of any machining operations. This makes it more versatile in most machining operations.
FAQs
Is Milling the Same as Turning?
No, milling is not the same as turning. They are fundamentally different machining processes.
Is Turning Faster than Milling?
Yes, unlike milling, in most cases turning process is quite straightforward. Milling on the other hand, is slower since its tool tends to engage and disengage repeatedly.
Can you Mill on a Lathe Machine?
Yes, it’s possible to mill using lathe machine however, you will require a live tooling that you can mount on the lathe. At the same time, there should be a rotating turnter fixed on the tooling system.
