Electric vehicle manufacturers want more power from smaller and lighter drivetrains. That pressure has brought renewed attention to the axial flux motor.

Often called a “pancake motor” because of its flat shape, an axial flux motor looks very different from the cylindrical motors commonly used in EVs.

Key Takeaways

Axial flux motors direct magnetic flux mainly parallel to the shaft, unlike the radial flux design used in most conventional EV motors.
Their high power density comes from motor geometry, torque radius and active material use rather than the flat shape alone.
Core materials can include NGOES, selected GOES configurations, SMCs and amorphous alloys, depending on the magnetic path and operating frequency.
Manufacturing precision, cooling and continuous power remain major constraints as axial flux motors move into series production.

What Is an Axial Flux Motor?

An axial flux motor is an electric motor in which the main magnetic flux crosses the air gap roughly parallel to the axis of rotation.

In a conventional radial flux motor, the rotor usually sits inside a cylindrical stator and magnetic flux moves radially across the air gap.

An axial design instead places the rotor and stator as opposing discs. The electromagnetic interaction takes place across these flat surfaces, giving the motor its characteristic short, disc-like form.

This different geometry is what separates axial flux from the radial flux architecture used in most electric vehicles.

Axial Flux Motor vs Radial Flux Motor

The basic differences can be seen more clearly side by side.

Feature	Axial Flux Motor	Radial Flux Motor
Main flux direction	Parallel to shaft	Radial to shaft
Typical shape	Flat, disc-like	Cylindrical
Axial length	Relatively short	Generally longer
Effective torque radius	Can be relatively large	Based on cylindrical rotor geometry
Winding overhang	Can be reduced in some designs	Often more significant
Cooling	Highly design-dependent	Mature solutions widely available
Manufacturing	More specialized	Highly mature
EV packaging	Useful where axial space is limited	Established across most EV platforms

A flat shape alone does not explain the higher power density. The advantage comes from how the geometry changes torque production and active material use.

1789110630429-Axial Flux vs Radial Flux Motor.webp

Axial flux motor vs radial flux motor magnetic flux direction

Why Axial Flux Motors Can Achieve High Power Density

Larger Effective Torque Radius

Torque depends on both electromagnetic force and the radius at which that force acts.

In an axial flux motor, much of the active electromagnetic area can be positioned relatively far from the shaft. This gives the electromagnetic force a larger effective lever arm and helps produce high torque within a compact package.

Axial motor torque is sometimes described using simplified D³ scaling relationships under comparable conditions, which highlights the influence of motor diameter.

Shorter Magnetic Path

Some axial flux topologies also provide a relatively direct magnetic path between opposing rotor magnets.

A shorter magnetic circuit can reduce the amount of inactive iron required and improve the use of the core material.

Less Inactive Copper

The same principle applies to copper.

Winding end turns sit outside the active magnetic region. They add resistance, heat and weight but do not directly produce torque.

Some axial flux designs use concentrated or segmented windings with shorter end turns, allowing more of the copper to remain in the active part of the motor.

Common Axial Flux Motor Topologies

Axial flux motors can arrange their rotors and stators in several ways.

Topology	Basic Layout	Main Difference
Dual-rotor / single-stator	One stator between two rotors	Compact structure with opposing rotor discs
Single-rotor / dual-stator	One rotor between two stators	Different mechanical and cooling arrangement
Yokeless segmented design	Individual stator segments without a conventional stator yoke	Reduces inactive iron and changes the magnetic path

1789110633420-Common Axial Flux Motor Topologies.webp

Common axial flux motor topologies including dual rotor and yokeless segmented designs

YASA is one of the best-known examples of the third approach. Its name comes from Yokeless And Segmented Armature.

Instead of using a conventional continuous stator yoke, the design divides the stator into individual electromagnetic segments. This can reduce inactive iron and motor mass, but it also changes how the stator is manufactured and how magnetic material is selected.

Magnetic Materials in Axial Flux Motors

Axial flux motors can use several types of soft magnetic materials. The choice depends largely on the magnetic path, operating frequency and stator geometry.

Electrical Steel: NGOES and GOES

Non-grain-oriented electrical steel (NGOES) remains a common choice for electric motors because its magnetic properties are relatively uniform in different directions within the sheet plane. Thin laminations also help control eddy-current loss as motor speed and electrical frequency increase.

Grain-oriented electrical steel (GOES) is more commonly associated with transformers because its magnetic properties are strongest along the rolling direction. In conventional radial motors, changing flux directions make this difficult to use effectively.

In selected axial flux or reluctance-type designs, the magnetic path can become more directional. This has led researchers to explore whether GOES can be aligned with the dominant flux direction to take advantage of its anisotropic magnetic properties.

Other Soft Magnetic Materials: SMCs and Amorphous Alloys

Electrical steel is not the only option.

Soft Magnetic Composites (SMCs) can be pressed into complex three-dimensional shapes, which is useful when the magnetic path is difficult to build from conventional stacked laminations. Recent motor-design work has also explored SMCs for high-performance axial flux applications, where their isotropic magnetic properties can better accommodate three-dimensional flux paths.

Amorphous alloys address a different issue. Their very thin ribbon structure and high electrical resistivity can help reduce eddy-current loss, making them attractive for higher-frequency motor applications.

The main challenge is processing. Amorphous ribbon is much thinner and more difficult to cut, form and assemble than conventional electrical steel.

Even so, amorphous materials are moving beyond laboratory research. Studies have already tested amorphous magnetic stator cores in axial flux motors, including yokeless segmented designs.

At the industrial level, HWHG has achieved mass production of iron-based amorphous ribbon and automotive-grade amorphous magnetic materials, with the material already moving into electric motor stator-core applications for China’s new-energy vehicle industry.

HWHG Amorphous Alloy Production Line

HWHG iron-based amorphous alloy ribbon mass production line

Cooling: Peak Power vs Continuous Power

Peak power density attracts attention, but an EV traction motor must also sustain useful power over time. Current in the windings produces copper losses, while the magnetic core and other components generate additional heat. If that heat cannot be removed quickly enough, motor output has to be reduced.

Axial flux architectures can create opportunities for more direct cooling. In some designs, oil or liquid coolant can reach the stator windings more directly, reducing the distance heat must travel from the copper to the cooling medium.

But cooling performance depends on the rotor and stator arrangement. A compact motor package does not automatically mean an easier thermal design.

Why Axial Flux Motors Are Harder to Manufacture

One of the main challenges is maintaining a small and uniform axial air gap between the rotor and stator.

Axial motors can experience strong magnetic attraction between opposing components. Rotor flatness, bearing position and assembly tolerances therefore have a direct effect on both electromagnetic performance and mechanical reliability.

Stator construction can also be more demanding.

Segmented and yokeless designs reduce inactive material, but individual stator teeth, windings and supporting structures still have to be positioned accurately. This may require specialized processes rather than the mature stamping, stacking and winding methods used for conventional radial motors.

A lighter motor does not automatically mean a cheaper motor. Specialized tooling, tighter tolerances, cooling integration and more complex assembly can all influence production economics.

Where Axial Flux Motors Fit in EVs

High-performance vehicles have been an early fit for axial flux motors because low weight and high power density matter more in this segment.

YASA is one of the best-known commercial examples. The company became part of Mercedes-Benz in 2021, and its technology is now moving from specialist applications toward series-production vehicle programs.

In October 2025, YASA reported that a 12.7 kg axial flux prototype motor produced 750 kW of short-term peak power, equivalent to 59 kW/kg. The company estimated continuous output at around 350–400 kW.

The gap between peak and continuous output is important because thermal limits still determine how much of that performance can be sustained.

Axial flux motors can also suit compact e-axles, where their short axial length gives engineers more flexibility when packaging the motor with the inverter, gearbox and differential.

Another possible application is the in-wheel motor. The flat geometry and high torque potential fit some direct-drive layouts, although unsprung mass, durability and cooling remain important constraints.

Mercedes-Benz began large-scale production of an axial flux motor at its Berlin-Marienfelde plant in 2026.

Conclusion

Axial flux motors will not replace radial machines across every EV platform. But where low weight, compact packaging and high power density matter most, they are becoming a more practical production option.

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