Choosing the Right Thin Gauge Electrical Steel for EV Motor lamination stacks

Welcome to the guide “Choosing the Right Thin Gauge Electrical Steel for EV Motor Core.” We are a professional motor lamination manufacturer based in China, dedicated to shaping the future of electric mobility through cutting-edge engineering and innovation.

With years of expertise in crafting custom EV motor lamination stacks, we understand the pivotal role that thin gauge electrical steel plays in the performance of electric motors.

In this comprehensive guide, we will introduce selecting the thin gauge electrical steel for your automotive motor core. We will explore the various types of electrical steel, key properties to consider, and the significance of customization. 

Additionally, We will unravel the essential processing techniques, including laser cutting, stamping, stacking, and insulation coating, that must seamlessly integrate with your steel selection to create a high-performance motor core.

What is Thin Gauge Electrical Steel?

Thin-gauge electrical steel, often referred to as laminations or cores, serves as the foundation of electric motors. Its primary function is to channel and optimize the flow of magnetic energy within the motor, allowing for the conversion of electrical energy into mechanical motion.

One of the most important factors to consider when choosing thin gauge electrical steel for EV motor cores is its magnetic properties. These properties determine how efficiently the steel can conduct and sustain a magnetic field.

Permeability and core loss are two key magnetic characteristics that directly impact motor performance.

Permeability, a measure of how easily a material can be magnetized, is crucial for efficient energy conversion. High permeability enables better magnetic flux and reduces eddy current resulting in improved motor performance.

On the other hand, core loss, also known as iron loss, represents the energy dissipated as heat within the steel when subjected to magnetic fields. Lower core loss is desirable as it minimizes heat generation and increases the motor’s efficiency.

electrical steel

Types of Lamination Materials

There are several types of thin gauge electrical steel available, each with its unique properties and applications. Understanding these varieties is essential in making the choice of the right materials for your EV application.

Silicon Steel (Silicon-Electrical Steel)

Silicon steel is perhaps the most common choice for EV motor cores due to its excellent electrical conductivity and magnetic properties. We commonly use electrical steel laminations ranging from 0.1 to 1 millimeter (mm).

In addition, we use thicknesses and grades of electrical steel like M15, M19, M22, M27, M36, M45, etc.

Non-Oriented Electrical Steel(NOES)

Non-oriented electrical steel is prized for its isotropic properties, which means it exhibits consistent magnetic properties in all directions. This makes it suitable for motors where the magnetic field changes direction frequently.

Grain-Oriented Electrical Steel(GOES)

Oriented electrical steel is designed with a preferred magnetic direction, resulting in enhanced performance in that specific direction. It is often used in motors with a predominant magnetic field direction.

Key Properties to Consider

Apart from magnetic properties, several other key properties should be considered when selecting thin gauge electrical steel for EV motor cores. These properties can significantly influence the motor’s performance and longevity.

Grain Orientation plays a vital role in determining the magnetic properties of electrical steel. Grain-oriented steel is engineered to have its grains aligned in a specific direction, resulting in improved performance in that orientation.

In contrast, non-oriented steel exhibits random grain orientation and is suitable for applications where the magnetic field varies.

Coating and Insulation are essential for protecting the steel from environmental factors and preventing electrical shorts. Thin gauge electrical steel is often coated with insulating materials to ensure that the laminations do not come into direct contact with each other.

How to choose this Gauge Electrical Steel for an EV Motor?

Selecting the right thin gauge electrical steel involves aligning the material’s properties with the specific requirements of your EV motor.

The design of your motor, including its size, shape, and intended application, should guide your choice of electrical steel. Different motor designs may require different steel properties for optimal performance.

Depending on the efficiency goals of your motor, you may need to prioritize certain properties, such as low core loss or high permeability. Efficiency is a critical factor in the overall performance of EV motors.

Minimizing core loss and heat generation is essential, especially in EVs where energy efficiency is paramount. Choosing electrical steel with low core loss helps reduce heat buildup, improving the motor’s lifespan and performance.

Processing Thin Gauge Electrical Steel for EV Motor Cores

The journey from raw thin gauge electrical steel sheets to a fully functional EV motor core involves several essential processing steps. These steps include laser cutting, stamping, stacking, and insulation coating, each playing a crucial role in shaping the final product.

Laser Cutting

Laser cutting is a precise and efficient method for shaping thin gauge electrical steel sheets. It allows for intricate designs and minimizes material wastage and tight tolerances laminations.


Stamping is the process of punching out laminations from the electrical steel sheets. But the thinner the electrical steel, the more challenging it is to stamp, especially when complex geometries are inherent in the lamination design. The flimsiness of thinner materials poses significant challenges in the stamping process.

The thinner lamination material, the more challenges progressing the material through the stamping die, and the end result if not addressed properly could create waffling or creasing in the material which can cause irregular gaps between lamination layers or non-conforming parts. 

At these thin gauges, punching is more of a controlled tear that is highly dependent on the quality and regular maintenance of the tooling, integrity of the laminations, and removal of parts from the die without damaging laminations also poses certain challenges.


Stacking involves assembling the stamped laminations to create the motor core. The stacking and bonding methods include riveting, cleating, laser welding, gluing, self-bonding, etc. The alignment of laminations is critical to maintaining the desired magnetic properties and minimizing core loss.

Insulation Coating

To prevent electrical shorts and protect the core from environmental factors, an insulation coating is applied to the laminations. This coating must be carefully selected to maintain the core’s magnetic properties.

lamination stacks of industry motor cores

Customization of EV motor core From Motorneo

One of the significant advantages in the world of thin gauge electrical steel is the ability to customize solutions to meet specific EV motor stator and rotor core requirements.

Customization ensures that the electrical steel selected and the processing techniques employed are tailored to the unique needs of your application.

Whether you require specific dimensions, grain orientations, or insulation coatings, Motorneo can deliver customized motor lamination materials.

We have multiple automation laser-cut machines to manufacture high-quality and tight tolerances rotor and stator lamination stacks. Ensuring your electric motor and generator have high throughput and efficiency.


Choosing the right thin gauge electrical steel for EV motor cores is a multifaceted decision that can profoundly impact the performance and efficiency of electric vehicles.

The selection process involves considering magnetic properties, grain orientation, insulation coatings, and customizations tailored to your motor’s requirements.

Additionally, processing techniques such as laser cutting, stamping, stacking, and insulation coating must align with the chosen electrical steel to maximize motor performance.


What factors should I consider when procuring thin gauge electrical steel and processing services?

When procuring thin gauge electrical steel and processing services for EV motor cores, there are several tips to keep in mind to ensure a successful partnership:

Supplier Reputation: Choose a supplier with a proven track record of delivering high-quality electrical steel and processing services. Look for testimonials and references from other EV manufacturers.

Quality Standards: Verify that the supplier adheres to industry quality standards and certifications. This ensures that you receive materials and services that meet the highest quality requirements.

Customization Capabilities: Ensure that the supplier can accommodate your customization needs, including specific dimensions, grain orientations, and insulation coatings.

Cost-Effectiveness: While quality is paramount, it’s also essential to consider the cost-effectiveness of the materials and services. A balance between quality and cost is key.

Long-Term Benefits: Look beyond immediate costs and consider the long-term benefits of your procurement choices. High-quality materials and processing can lead to lower maintenance costs, increased efficiency, and enhanced product lifespan.

How do magnetic properties like permeability and core loss impact EV motor performance?

Permeability determines how easily a material can be magnetized and affects magnetic flux, while core loss represents energy dissipation as heat. High permeability and low core loss are desirable for efficient motor performance.

Why 0.2mm Silicon Steel Stamping Is More Expensive?

0.2mm silicon steel stamping is pricier due to its scarcity, precision demands, and unique properties. Thinner sheets minimize core loss, enhancing energy efficiency, but their production requires meticulous precision, often leading to higher manufacturing costs.

Try to contact us for high-quality motor cores in China.