Your CNC Machine Has Five Axes—But Are You Really Using All Five?

Buying a 5-axis CNC machine is a major investment.

But here's a question many manufacturers don't ask after the machine arrives:

Are you actually using all five axes?

A machine may have three linear axes and two rotary axes, but that doesn't necessarily mean all five axes are moving during every machining operation.

In fact, many five-axis jobs are programmed using 3+2 machining, where the rotary axes position the workpiece or cutting tool before the actual cutting operation takes place.

There is nothing wrong with that.

3+2 can be extremely effective for many applications.

But if your parts require continuously changing tool orientations, complex freeform surfaces, deep cavities, or difficult transitions, you may be leaving a significant part of your machine's capability unused.

So what is the difference between having five axes and using five axes?

Five Axes Does Not Mean Five Axes Are Always Moving

Let's start with the basics.

A typical five-axis machining center combines:

• X axis
• Y axis
• Z axis
• Two rotary axes

The three linear axes control the position of the cutting tool.

The two rotary axes change the orientation of the workpiece and/or cutting tool.

Together, these axes allow the machine to approach a component from significantly more directions than a conventional three-axis machining center.

But there are different ways to use those axes.

The two most common approaches are:

3+2 machining

and

Simultaneous 5-axis machining

Understanding the difference is critical if you want to get the most out of a 5-axis CNC machine.

What Is 3+2 Machining?

In 3+2 machining, the rotary axes are used to position the workpiece or cutting tool at a specific angle.

Once the desired orientation is reached, the machine performs the cutting operation using the three linear axes.

For example:

Position → Lock/maintain orientation → Machine → Reposition → Machine again

Imagine a component with features on five different surfaces.

Instead of physically removing the part and changing the fixture, the machine can rotate the component to expose another surface.

The cutting itself can then be performed using conventional three-axis movement.

This is why 3+2 machining can dramatically reduce setups.

Why 3+2 Is Still Extremely Useful

Some manufacturers assume that 3+2 machining is somehow an inferior version of five-axis machining.

That's not necessarily true.

For many applications, 3+2 machining is exactly the right strategy.

It can provide:

Fewer setups

The machine can access multiple sides of a component without manually repositioning the workpiece.

Better accessibility

Angled features become easier to reach.

Simpler programming

Compared with simultaneous five-axis toolpaths, 3+2 strategies can often be easier to program and verify.

Improved tool access

Tilting the tool or workpiece can help avoid interference and allow shorter tools to be used.

Better rigidity

A fixed cutting orientation can sometimes provide a more stable machining condition than continuously changing the tool angle.

So the question isn't:

"3+2 or 5-axis—which one is better?"

The better question is:

"Which machining strategy is best for this part?"

Then What Is Simultaneous 5-Axis Machining?

This is where things become more interesting.

In simultaneous 5-axis machining, all five axes can move together during the cutting operation.

The three linear axes control the tool position.

The two rotary axes continuously adjust the tool orientation.

Instead of:

Position → Cut → Reposition → Cut

the machine can perform:

Position + Orientation + Cutting — continuously

This creates a completely different machining capability.

The tool can follow complex three-dimensional surfaces while continuously changing its angle relative to the workpiece.

For certain components, this can be the difference between a practical machining process and a very difficult one.

Why Tool Orientation Matters

Here's something easy to overlook:

Five-axis machining isn't just about reaching more surfaces.

It is also about controlling the angle of the cutting tool.

Consider machining a curved surface.

On a three-axis machine, the tool orientation is relatively limited.

The machine can move the tool along X, Y, and Z, but the tool axis remains essentially fixed.

As the surface becomes steeper or more complex, this can create problems.

You may need:

• Longer tools
• Multiple setups
• Smaller stepovers
• More finishing passes
• Additional fixtures

With simultaneous 5-axis machining, the cutting tool can continuously adjust its orientation as it follows the surface.

This can help maintain a more suitable cutting angle.

The Difference Becomes Obvious on Complex Parts

Consider parts such as:

• Turbine blades
• Impellers
• Aerospace structural components
• Medical implants
• Complex molds
• Automotive components
• Energy components
• Precision dies
• Complex prototypes

These parts often contain surfaces that cannot be efficiently machined from a single fixed tool orientation.

This is where simultaneous five-axis movement becomes particularly valuable.

The machine isn't simply moving the part.

It is continuously controlling the relationship between the tool and the surface being machined.

Are You Really Using All Five Axes?

Here's a simple way to evaluate your current process.

Ask yourself:

1. Are the rotary axes only used to position the part?

If yes, you're primarily using 3+2 machining.

That may be completely appropriate—but you're not using simultaneous five-axis motion.

2. Does the tool orientation change during cutting?

If yes, you're moving toward true simultaneous five-axis machining.

3. Are you still using multiple setups?

If your five-axis machine is primarily being used to replace several setups on relatively simple parts, you're already getting value from it.

But there may be additional opportunities.

4. Are you using long tools to reach deep areas?

A different tool orientation may allow you to use a shorter, more rigid tool.

5. Are complex curved surfaces requiring many finishing passes?

This may indicate an opportunity to use continuous tool-axis control.

Five-Axis Capability Is More Than an Axis Count

When evaluating CNC machines, it is easy to compare specifications like:

3-axis vs. 5-axis

But axis count alone doesn't tell the whole story.

Two machines may both be called five-axis machines while delivering very different machining performance.

You should also consider:

• Rotary-axis range
• Rotary-axis speed
• Rotary-axis accuracy
• Rotary-axis repeatability
• Spindle performance
• Machine rigidity
• Thermal stability
• Control system
• CNC interpolation capability
• CAM compatibility
• Post-processor quality
• Machine kinematics

For precision machining, these factors can be just as important as the number "5".

Your CAM Software Matters Too

There's another common misconception:

If I have a five-axis machine, my existing CAM workflow will automatically use five axes.

Not necessarily.

The machine and CAM software need to work together.

A five-axis machining process typically requires:

CAD Model → CAM Strategy → Toolpath → Post Processor → CNC Control → Machine Kinematics

If the toolpath is designed for three-axis or 3+2 machining, the machine cannot magically turn it into simultaneous five-axis machining.

The CAM strategy must deliberately control the additional rotary axes.

This is why choosing the right CAM software and post processor is an important part of implementing 5-axis CNC machining.

Don't Use Simultaneous 5-Axis Just Because You Can

There is also a trap on the opposite side.

Once manufacturers purchase a five-axis machine, they may feel that every job should be programmed as simultaneous five-axis machining.

That's not a good rule.

For some parts, simultaneous five-axis movement can make programming more complicated without providing a meaningful manufacturing benefit.

For example, if a component has several simple angled surfaces, a 3+2 strategy may be faster and easier.

A good five-axis programmer doesn't ask:

"How can I use all five axes?"

They ask:

"How can I use the available axes to produce this part better?"

That's an important distinction.

When Should You Use 3+2?

3+2 machining is often a good choice when:

• The part has multiple angled faces
• Features need to be accessed from different directions
• The cutting surfaces are relatively simple
• Tool orientation doesn't need to change continuously
• You want simpler programming
• You want to reduce setups
• Rigidity is a priority

For these applications, 3+2 can deliver much of the practical value of a five-axis machine without requiring complex simultaneous toolpaths.

When Should You Use Simultaneous 5-Axis?

Simultaneous five-axis machining becomes more attractive when:

• Surfaces are highly curved
• Tool orientation must continuously change
• The tool needs to maintain a specific contact angle
• Deep cavities create tool-access problems
• Long tools are causing vibration
• Surface finish is critical
• Multiple complex surfaces transition into one another
• Conventional machining requires excessive setups or finishing

In these situations, using all five axes simultaneously can fundamentally change the machining strategy.

The Hidden Benefit: Shorter Tools

One of the less obvious advantages of five-axis machining is tool length.

Imagine a deep feature that requires a long cutting tool on a three-axis machine.

The longer the tool extends from the holder, the greater the potential for:

• Deflection
• Vibration
• Poor surface finish
• Reduced cutting stability

By tilting the tool using five-axis motion, the cutting tool may be able to approach the surface more effectively.

This can allow a shorter tool to be used.

And sometimes:

Better tool orientation → Shorter tool → Greater rigidity → Better machining performance

That's a benefit that has nothing to do with simply reducing setups.

Five-Axis CNC Is About Freedom of Movement

Ultimately, the real advantage of five-axis technology is machining freedom.

A three-axis machine essentially asks:

"How can I reach this surface from my current tool orientation?"

A five-axis machine gives you another question:

"What is the best tool orientation for machining this surface?"

That is a fundamentally different way of thinking about manufacturing.

Instead of designing the process around the limitations of the machine, you can design the machining strategy around the geometry of the part.

How to Get More From Your 5-Axis CNC Machine

If you already own a five-axis machine, you don't necessarily need to replace it to get more value.

Start by reviewing your current parts.

Look for components that:

• Require three or more setups
• Have complex curved surfaces
• Require long cutting tools
• Have difficult-to-reach areas
• Need extensive finishing
• Experience positioning problems between setups
• Require complicated fixtures

Then ask:

Could a different tool orientation simplify this operation?

Could 3+2 eliminate some setups?

Could simultaneous 5-axis reduce finishing work?

Could a shorter tool improve cutting stability?

This exercise can reveal opportunities that were hidden in your existing production process.

The Five Axes Are Only Valuable When You Use Them Strategically

A five-axis CNC machine gives you significantly more freedom than a three-axis machine.

But simply having five axes doesn't guarantee better machining.

The real value comes from knowing when, where, and how to use them.

Sometimes that means 3+2.

Sometimes it means simultaneous five-axis machining.

And sometimes a conventional three-axis strategy is still the most efficient choice.

The best manufacturers don't use five axes for the sake of using five axes.

They use them when the additional freedom produces a measurable advantage in:

precision, accessibility, surface quality, tooling, setup reduction, or production efficiency.

So the next time you look at your five-axis CNC machine, ask yourself:

Are you really using all five axes—or are you only using the machine as a more expensive three-axis machine?

The answer could reveal your next major opportunity for improving your machining process.

Frequently Asked Questions

What is the difference between 3+2 and simultaneous 5-axis machining?

3+2 machining uses the rotary axes to position the workpiece or cutting tool at a fixed orientation before three-axis cutting. Simultaneous 5-axis machining allows all five axes to move together during the cutting process.

Is 3+2 machining considered five-axis machining?

Yes. 3+2 machining uses a five-axis machine, but the two rotary axes generally position the cutting orientation rather than continuously moving during cutting.

Does simultaneous 5-axis machining always produce better results?

Not necessarily. The best strategy depends on part geometry, tooling, material, tolerances, surface requirements, and production goals. 3+2 can be more efficient for many parts.

Does five-axis machining reduce setups?

It can. A five-axis CNC machine can access multiple sides and angled features without requiring the workpiece to be manually repositioned between every operation.

Why is tool orientation important in 5-axis machining?

Changing tool orientation can improve access to complex surfaces, help maintain a suitable cutting angle, reduce tool length, and potentially improve surface finish and machining stability.

What CAM software is needed for simultaneous 5-axis machining?

Simultaneous five-axis machining requires CAM software capable of generating five-axis toolpaths and a suitable post processor configured for the specific machine's kinematics and CNC control.

How can I determine whether my current five-axis machine is being fully utilized?

Review your current machining programs and look at how the rotary axes are being used. If they are only used to position the part before cutting, you are primarily using 3+2. If the rotary axes continuously change orientation during cutting, you are using simultaneous five-axis machining.