3,4,5 Axis of CNC: What’s the Difference?

Updated: May 11, 2024

Many guides may have already written a lot on CNC machining. But do they make it clear how computer-controlled centers with a different number of axes suit one or another particular manufacturer’s needs?

It is still difficult to obtain proper insight into the specificities of 3, 4, and 5-axis machines intended for distinct purposes. Insufficient choice of a CNC machine would always result in a lack of quality of components produced or extra expenses.

This post will detail each type of centers for material shaping, explain the vital differences, and provide suggestions for their choosing.

1. What is a 3 Axis Machine?

A 3-axis machine is referred to as the basic and most widely used type of CNC centers, which may be a mill, lathe, turning machine, drill, grinder, router, or any other. The distinct feature of 3-axis machines is having 3 axes known as X, Y, and Z ones, serving the purpose of moving a cutting tool or a workpiece along them while shaping material.

The way all the three axes of a standard CNC machine operate is visualized in the short gif below.



It is possible to observe that such machining enables the cutting of the front of a workpiece, shaping basic contours with a variety of cutting tools.

It is enough for like 70% of simple designs which can be created with a help of one or another CNC center. However, the need for more intricate shapes and more advanced machines were raised years ago

2. Simplified 3 Axis Machining

Just to be precise, there are also 2-axis machines intended to remove a material with a spindle moving only along X and Y dimensions. Their straight-line moves can be performed in the third axis, but it is not technically considered fully featured 3 axis machining.

At the same time, there are 2.5 axis machines, an example of which is a two-and-a-half-axis mill. Such machines are capable of translating in all three axes, but the simultaneous cutting operations can be performed along 2 axes only.

Both 2 and 2.5 axis machines are considered simplified, modified, or adapted versions of basic 3-axis machines.

3. What is a 4 Axis Machine?

A 4-axis machine is an advanced version of a 3-axis one with an added A-axis. The way all the four axes of a CNC machine operate is visualized in the short gif below.

4th Axis CNC


A-axis is a rotational one, which enables the repositioning of a workpiece while machining. Based on the time of a machine, it may be capable of removing material while rotating, or only while a workpiece is blocked.

It does not make more complex designs as a 3-axes center does, as basically rearranging of a workpiece can be done manually.

4. What is a 5 Axis Machine?

A 4-axis machine goes beyond improving precision or making it unnecessary to reposition a workpiece than its other side should be shaped. Adding rotations about the X-axis known as B / C axis (clockwise and counterclockwise respectively) boosts the range of designs that can be created with such a CNC center.

The way all the five axes of an advanced CNC machine operate is visualized in the short gif below.



Deriving from the increased variety of angles, in which a workpiece can be cut, a 5-axis machine can offer additional operations.

Milling, turning, routing, and other types of machining can be performed by an advanced CNC center, making it both effective while shaping intricate designs and complicated in preparing and maintenance.

Related Post: 5 Axis CNC Machining: Definition, Benefits and Types

5. What is the Difference?

Considering a 3-axis CNC machine as a referential model, it is possible to outline key discrepancies between it and 3 and 4 axis automated centers.

The difference between a 3 and 4 axis CNC machine is a more production-focused one. It implies that it affects the capability of a manufacturer to produce higher numbers of components within shorter terms.

The mechanism of action is basically the same for both 3 and 4 axis centers, and the components’ potential complexity is not changed either.

However, due to enabling rotation of a workpiece, there is no need to rearrange its fixed position before designing another side, which is beneficial for production rates.

The principal difference between 3 and 4 and between 3 and 5 axis machines is extra options enabled by the additional dimension.

Despite neither accuracy nor production rates being benefited from the most advanced machine, it makes it possible to create intricate designs, which may be required for some components and parts.

Therefore, while a 4 axis machine increases only the quality and quantity of components produced, the 5-axis one offers to perform additional operations at any angle increasing the range of potential designs.

6. How to Choose 3, 4, or 5 Axis CNC Machining?

Considering the purchase of a CNC machine you need to pay attention to some key points that may impact the final decision positively. Basically, there are some situations when buying a 4 or 5 axis machine instead of a 3-axis one is justified, and some cases when a basic CNC center is a more reasonable choice.

When You Need More Advanced CNC Machine

  1. A basic piece of machinery is not capable of cutting away material in hard-to-reach sections of a workpiece in needed designs.
  2. Your manufacturer has large-scale orders that should be prepared in a limited time and you do not want a reduction in productivity because of the need to carry out multiple setups.
  3. our company may sustain additional expenses to cover up the projected demand for complex components, even if there is no such current need.
  4. Precision and accuracy are of greater importance compared to maintaining production costs low.

When You Do Not Need More Advanced CNC Machine

  1. Capital is scarce, and it is not likely that projected orders for complex components are justifying extra expenses.
  2. Your company is focused on the production of components with simple designs only.
  3. You do not have specialists of partners that can perform pre-programming and constant maintenance of a more advanced machine regularly.
  4. To 4-axis machines, you do not need one if your manufacturer only produces components to be shaped from the front side.

The optimal CNC machine may be chosen based on a manufacturer’s current situation and needs.

7. Summary

Basic 3-axis centers or their simplified versions are widespread and optimal for some cases. They are more affordable, less complex in preparation and maintenance, and suit most necessities of certain manufacturers.

However, more and more enterprises producing components find their standard equipment unit to not be sufficient enough.

4-axis machines can provide more precision and speed up production rates, making large-scale orders manageable. Simultaneously, 5-axis centers are all-in-one solutions offering any intricate designs in exchange for difficulty operating and extra expenses needed.

Carefully decide on purchasing a CNC machine based on the orders projected.

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