CNC (Computer Numerical Control) machines have transformed the whole manufacturing industry by using computer software to control machines. This technology precisely removes excess material from raw stock. Ultimately, they can produce parts that meet exact specifications.

There are different CNC processes, with CNC turning and milling machines being the most common ones. Manufacturers should select the proper technique to achieve the perfect product. This article explores the critical differences between these two machining techniques and discusses some of their applications. Let’s discover how these processes can enhance your manufacturing capabilities!

What is CNC Turning?

CNC turning is a machining process where a workpiece is rotated in a chuck while cutting tools remove material to achieve the desired shape.

In the past, manufacturers had to operate lathes manually, which was labor-intensive. Then, the CNC program came with software that automates various tasks such as boring, drilling, facing, grooving, and parting.

A CNC lathe has two primary components:

  • Multi-sized cutting tool: The machinist programs the speed, depth, feed rate, and other instructions so that the cutting tool performs its tasks accurately and automatically.
  • A chuck: This component secures the workpiece as cutting tools move toward it, shaping it as needed.

What is CNC Milling?

Similar to CNC turning, CNC milling is a computer-controlled machining process with various tasks, such as plain milling, face, and angular, to produce accurate components from suitable materials.

A CNC milling machine comprises multiple components, each with specific jobs:

  • A spindle: The vertical spindle holds and rotates the cutting tools.
  • Multi-point cutting tool: The cutting tool progressively removes material from the workpiece.
  • Axes: The axes come in different configurations that guide the movement of the cutting tools. While 3-axis mills move in X, Y, and Z directions, 5-axis machines allow more flexibility.
What is CNC Milling?
CNC Milling

Turning and Milling Similarities

Many people confuse turning and milling processes because of the similarities between them. For example:

  • Subtractive manufacturing: Both CNC turning and milling use subtractive manufacturing, where the machines get rid of unwanted material from stock to shape the final product. This process generates chips of removed material as the tools cut away excess material.
  • CNC technology: Engineers create machines using Computer-Aided Design (CAD) software to reduce the need for constant supervision and minimize human error. This approach ensures faster, more consistent production quality.
  • Material compatibility: Both processes are suitable for machining various materials like steel, brass, titanium, aluminum, thermoplastics, and copper. However, they can’t work with rubber, which is too soft, and ceramic, which is too hard.
  • Heat generation and cutting fluids: Milling and turning generate heat during machining. Hence, both often use cutting fluids to cool the workpiece and tools.
Turning and Milling Similarities
What Milling and Turning Have In Common?

What Are the Differences Between CNC Turning and Milling?

The most noticeable between CNC turning and milling is the movement of the tools and workpiece. In a turning process, the workpiece rotates while the cutting tool remains stationary. On the other hand, in milling, the cutting tool rotates and the workpiece stays in place. This fundamental distinction leads to other differences between the processes:

Features CNC Turning CNC Milling
Suitable Materials Highly adaptable to various materials, including plastics, metals, and wood. More selective, commonly used for carbon steel, stainless steel, nylon, titanium, and aluminum.
Tool Features Employs a single-point cutting tool, where the cutting edge removes material by direct contact as the workpiece rotates. Uses a multi-point cutting tool with several cutting edges, allowing for faster cutting.
Uses Best for conical or cylindrical shapes, such as shafts, nozzles, firearms, and turbines. Perfect for irregular, complex, or flat surfaces like gears, brackets, water pumps, housings, and enclosures.
Cutting Features continuous cutting, where the tool remains in constant contact with the workpiece as it rotates. Uses intermittent cutting, where the cutter keeps engaging and disengaging from the workpiece.
Chips CNC turning can generate fragmented, continuous, or discontinuous chips. CNC milling produces discontinuous chips because the tool continuously engages and disengages the material.
Machining Operations Includes operations like boring, threading, knurling, drilling, straight turning, and taper turning. Includes profiling, face milling, angular milling, and plain milling.
Shapes Produced Produces axially symmetrical shapes like cones, disks, polygons, and cylinders. Produces both symmetrical and non-symmetrical shapes.
Function Mechanism The workpiece rotates while the cutter remains stationary. The cutter rotates, but the workpiece doesn’t move.
When to Choose the Right One – Best for parts that require rotational symmetry.
– Producing parts with round profiles.
– High-volume manufacturing of tubular components.
– Ideal for machining non-cylindrical parts.

– Acting as secondary finishing thanks to its well-defined design features.

– Handling intricate parts with multiple surface features.

 

Examples of Parts Made With CNC Turning And Milling Machines

CNC turning and milling machines are versatile tools used across various industries.

CNC turning works best in these cases:

  • Rounded profiles: Shafts and turbines
  • Reinforcement components: Flanges and ball joints
  • Industrial parts: Rollers and nozzles
  • Precision components: Firearms, bolts, and nuts

CNC milling is more suitable for detailed machining, allowing it to shine in the following projects:

  • Hydraulic components: Water pumps and forming punches
  • Housing parts: enclosures, housings, and brackets
  • Mechanical devices: Gears and fittings
  • Production tools: Mold tooling, blocks, and automotive components
Examples of Parts Made With CNC Turning And Milling Machines
Different Uses Of Milling And Turning

Why Work With Fischer Asia?

Looking for a reliable partner for your CNC turning and milling machine needs? Fischer Asia is excellent at customizing metal stamping parts and precision molds, ensuring high-quality, consistent results for complex metal operations. We design and manufacture robust stamping molds and tooling solutions to deliver solutions with unmatched quality. Contact us today to succeed in your next project with excellence!