What is Difference Between CNC Milling and Turning, Which Should I Use?

 

Introduction

Definition of CNC Milling and Turning

In the realm of modern manufacturing, CNC milling and turning stand as two fundamental subtractive manufacturing processes, playing crucial roles in creating precision parts and components across a wide array of industries.

CNC milling is a process that uses a rotating cutting tool, typically an end mill, to remove material from a stationary workpiece. The tool has the ability to move along multiple axes, usually the X, Y, and Z axes. This multi - axis movement enables the creation of complex shapes and features, making it a go - to choice for parts with intricate designs. For example, in the aerospace industry, CNC milling is often used to create parts for aircraft engines, where complex geometries are required to optimize performance.

On the other hand, CNC turning uses a stationary cutting tool to remove material from a rotating workpiece. The tool moves along the workpiece's axis, primarily the X and Z axes. This setup is highly efficient for creating cylindrical shapes and features. In the automotive industry, CNC turning is commonly employed to produce engine shafts, which need to be precisely cylindrical to ensure smooth operation.

1. Tools and Techniques Employed

Tools in CNC Milling

In CNC milling, the primary tool is a rotating end mill. End mills come in a wide variety of types, each designed to handle different machining tasks. For instance, a common type is the square - end mill, which is great for creating flat surfaces, slots, and pockets. It has a flat cutting edge at the end, allowing for precise machining of rectangular - shaped features. In the production of molds, square - end mills are often used to create the cavities and details that are essential for the final product.

Ball - nose end mills are another important type. As the name implies, they have a rounded cutting edge, similar to a hemisphere. These are ideal for machining 3D contours and curved surfaces. In the aerospace industry, when manufacturing components like turbine blades, ball - nose end mills are used to create the complex, curved shapes that are crucial for the blade's aerodynamic performance.

There are also corner - rounding end mills, which are used to create rounded corners on parts. This is important in many applications, as sharp corners can be stress - concentration points. For example, in the automotive industry, when machining engine components, corner - rounding end mills are used to improve the fatigue resistance of the parts.

The movement of the end mill in CNC milling is multi - axial. It can move along the X, Y, and Z axes, and in some advanced machines, even additional axes such as A and B axes. This multi - axis movement gives the operator the ability to create highly complex geometries. For example, in 5 - axis CNC milling, the tool can approach the workpiece from multiple angles, allowing for the creation of parts with undercuts, complex pockets, and intricate surface finishes.

Tools in CNC Turning

CNC turning, on the other hand, uses a stationary cutting tool. The most common types of cutting tools in CNC turning are single - point tools. These tools have a single cutting edge and are highly versatile for different turning operations. For external turning, a general - purpose external turning tool is used to remove material from the outer diameter of the workpiece, creating cylindrical shapes. This is commonly seen in the production of shafts for motors or engines, where the diameter of the shaft needs to be precisely controlled.

Internal turning tools are used to machine the inner diameter of a workpiece, such as creating holes or internal threads. For example, when manufacturing pipes or tubes with threaded ends, internal turning tools are used to cut the threads accurately.

more What is Difference Between CNC Milling and Turning, Which Should I Use?