electric motor lamination stacks by progressive die stamping

How To Manufacture Electrical Motor Lamination Stacks By Progressive Die Stamping?

Electric motor lamination stacks are integral components in the world of electromechanical systems. The demand for efficient and reliable motors has propelled the need for advanced manufacturing techniques. Manufacture motor lamination by progressive die stamping offers unparalleled precision and cost-effectiveness in the production process.

In this blog, we’ll explore the essential steps, materials, and equipment involved in creating these crucial stator rotor components for electromechanical systems.

From the basics of lamination stacks to the intricate details of progressive die stamping, we’ll break down the process into digestible insights.

Overview of Electrical Motor Lamination Stacks

understanding electric motor lamination

Electrical motor lamination stacks, also known as cores, play a pivotal role in enhancing motor efficiency. These stacks, often composed of silicon steel for their magnetic properties, are meticulously designed to optimize magnetic flux and minimize energy losses.

The primary function of these laminations is to enhance the motor’s performance by providing a path of least resistance for magnetic fields, reducing eddy current losses, and improving overall energy efficiency.

Progressive Die Stamping Process

Progressive die stamping is a metalworking process that efficiently produces large quantities of precision parts. Electric steel laminations, also known as electrical steel or silicon steel, commonly apply to the cores of electrical transformers, motors, and generators due to their magnetic properties. The progressive die stamping process for electric steel laminations involves several stages:

progressive stamping process

Material Selection:

Electric steel laminations are typically made of silicon steel or nickel cobalt alloy and thin-gauge electrical steel, which helps to reduce eddy current losses and improve magnetic properties.

Material Preparation:

The electric steel is usually supplied in coils or sheets. Before stamping, the material may undergo processes like leveling, cutting, and edge conditioning to ensure uniformity and proper dimensions.

Tool and Die Design:

Progressive stamping dies consist of a series of stations or steps, each performing a specific operation on the material. The die set is designed to progressively cut and form the material in multiple steps during a single stroke of the stamping press.


The first station of the progressive die cuts the electric steel into a basic shape known as a blank. This blank corresponds to the outline of the final rotor and stator part.


Subsequent stations perform piercing operations, creating holes or openings in the blank as required for the final part.


The silicon steel lamination undergoes various forming operations at different stations to shape it into the desired configuration. This may involve bending, drawing, or extruding the material.


Notching operations may be performed to create specific features or to accommodate other components in the assembly.

Assembly Operations:

In the case of laminations, the progressive die may interlock stacking multiple layers of laminations to achieve the desired thickness.

Final Grinding:

Additional stations perform final cuts, trims, or other operations to refine the part’s dimensions and ensure it meets the required specifications.

In conclusion, progressive die stamping is versatile and suitable for high-volume production, making it an ideal choice for industries where precision and efficiency are paramount.

Quality Control

quality control of electric motor cores

Incoming Material Inspection:

Verify the quality and specifications of the incoming electric steel coils/sheets. Conduct hardness tests to ensure the material meets the required standards.

First Article Inspection:

Perform a comprehensive inspection of the first few stamped motor laminations to validate tooling setup and initial production quality.

In-Process Inspections:

Conduct regular inspections during the progressive stamping process using CMM, 2.5D measurement devices, and digital height gauges to monitor dimensional accuracy and consistency.

Hardness Testing:

Randomly sample stamped laminations and perform hardness tests at specified intervals to ensure consistent material properties.

Salt Spray Testing:

Randomly select finished motor laminations and subject them to salt spray testing. Evaluate the results to verify the effectiveness of any applied protective coatings.

Final Inspection:

Perform a final inspection on all stamped motor laminations using CMM and other measurement tools to ensure compliance with design specifications. Reject any parts that do not meet the required standards.

Documentation and Reporting:

Maintain detailed records of inspections, measurements, and test results for each production batch. Generate comprehensive reports highlighting any deviations from specifications and the corrective actions taken.

Continuous Improvement:

Regularly review quality control data and implement continuous improvement initiatives to enhance the efficiency and precision of the progressive stamping process for motor laminations.

By incorporating these quality control measures and utilizing advanced measurement tools, the manufacturing process can consistently produce high-quality motor laminations that meet or exceed customer expectations.

Advantages Of Progressive Die Stamping

Progressive die stamping for motor stator and rotor laminations offers several advantages, making it a preferred manufacturing process in the production of electrical motors. Here are some key advantages:

High Efficiency and Speed:

Progressive die stamping is a highly automated process that allows for continuous, high-speed rotor and stator laminations. Multiple operations are performed in a single pass, reducing cycle times and increasing overall efficiency.


The high-speed production and automation in progressive die stamping contribute to lower labor costs per unit. Additionally, the process minimizes material waste, optimizing material utilization and reducing overall manufacturing costs.

Precision and Consistency:

Progressive dies are designed with precision to ensure consistent part dimensions. This high level of accuracy is crucial for the performance of electrical motors, where tight tolerances are often required.

Complex Geometries:

Progressive die stamping can easily accommodate complex part geometries and intricate shapes. This flexibility in design is beneficial for creating motor laminations with specific magnetic and structural properties.

Scalability for Mass Production:

Progressive die stamping is well-suited for large-scale production. It allows manufacturers to produce a high volume of motor laminations in a relatively short time, meeting the demands of mass production.

Reduced Secondary Operations:

The progressive die stamping process often incorporates multiple operations in a single die, reducing the need for additional secondary operations(such as riveting stacking). This can streamline the production process and decrease overall lead times.

Adaptability to Various Materials:

Progressive die stamping is adaptable to various materials, including different grades of electrical steel. This versatility allows manufacturers to choose materials that best suit the performance requirements of the motor.

Progressive die stamping offers a combination of speed, precision, cost-effectiveness, and scalability, making it a highly advantageous manufacturing process for motor laminations in the electrical motor industry.

Lamnow Motor Lamination Stamping Capabilities

Lamnow specializes in diverse stamping services, offering progressive stamping, compound stamping, rotary notching, and more. Our state-of-the-art facilities leverage advanced technology and precision tooling to deliver high-quality motor laminations. 

With expertise in various stamping techniques, we cater to unique design specifications, ensuring optimal performance and efficiency for a range of electrical motors.

Whether it’s progressive or compound stamping, rotary notching, or other specialized processes, Lamnow is committed to providing tailored solutions, meeting the stringent standards of the industry.  Lamnow excellence in stamped components supports the evolving needs of the electric motor sector.

lamination manufacturing capabilities


In conclusion, mastering the art of manufacturing electrical motor lamination stacks through progressive die stamping is a crucial endeavor for efficient and cost-effective production. The precision and speed offered by this technique ensure the creation of high-quality laminations that are vital components in electric motors.

By embracing progressive die stamping, manufacturers can achieve remarkable consistency in dimensions and minimize material waste. This process not only enhances productivity but also contributes to the sustainability of production methods.


What is the typical production volume achievable through progressive stamping for electric steel laminations?

Progressive stamping excels in high-volume production. The process allows for quick and efficient manufacturing, making it suitable for meeting the demands of large-scale electrical component production.

In what applications are motor laminations produced through progressive stamping commonly used?

Motor laminations produced through progressive stamping are commonly used in various applications requiring efficient and precise electric motor performance. These laminations find extensive use in industries such as automotive, appliances, HVAC systems, and industrial machinery.

The high-speed production capabilities of progressive stamping allow for cost-effective manufacturing of intricate motor components, contributing to the reliability and performance of electric motors across a wide range of applications.

How does the thickness of electric steel impact the progressive stamping process and the performance of laminated cores?

The thickness of the electric steel affects the magnetic properties of laminated cores. Proper control of material thickness is crucial in achieving optimal performance in electrical components.

Can you explain the concept of compound stamping in relation to progressive stamping?

Compound stamping involves multiple tooling stations on the same die to perform various operations simultaneously, allowing for more complex and intricate part designs. In comparison, progressive stamping involves a sequential process where the metal sheet advances through different stages to achieve the final form.

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