Electrical stamping is the process of pressing thin sheets of electrical-grade steel into precise laminations that are stacked to form the magnetic cores of motors, transformers and generators. The individual pressed part is also called a “stamping” or “lamination”.
The process
A coil of CRCA steel is fed into a high-speed power press fitted with a die. The die blanks out the lamination shape — complete with slots — in a single stroke. Thousands of identical laminations are produced, then stacked and interlocked or riveted into a core.
The materials
Most stampings use cold-rolled close-annealed (CRCA) electrical steel for its clean surface, uniform thickness and good magnetic properties. Thin, clean, electrically-separated laminations are what keep a core’s eddy-current losses low.
Why it matters
The quality of the stamping — steel grade, slot accuracy and burr control — directly sets how efficient and quiet the finished motor will be. That is why OEMs specify precision stampings over general pressings.
Explore the different core shapes we make: E-frame, H-frame and BLDC stampings, or see the full product range and how they serve industrial electric motors. Questions? Call +91 98991 00494.
What Is Electrical Stamping? Process, materials and uses
Electrical stamping is the process of punching thin sheets of electrical steel into precise shapes — called laminations — that are stacked to form the magnetic cores of motors, transformers, generators, pumps and fans. Because a solid iron core would waste energy through eddy currents, the core is instead built from many thin, insulated laminations. Stamping is how those laminations are made accurately and in volume.
The stamping process, step by step
- Blanking — the outer profile of the lamination is punched from the steel strip.
- Piercing / notching — slots, holes and vents are punched for windings and cooling.
- Progressive or compound die — for high volume, all features are formed in one press stroke.
- Stacking — laminations are interlocked, cleated, riveted or welded into a core.
- Annealing (if required) — relieves stress and restores magnetic properties.
Materials used
| Material | Best for |
|---|---|
| CRNGO silicon steel | Motors, generators — low core loss, non-directional |
| CRGO silicon steel | Transformers — grain-oriented, very low loss in one direction |
| CRCA steel | Cost-sensitive, moderate-duty laminations and components |
Where electrical stampings are used
- Stator and rotor cores of induction and BLDC motors
- Transformer and choke cores
- Submersible, monoblock and industrial pump motors
- Fans, alternators, generators and control gear
What separates a good stamping from a poor one
Three things: burr height (a low burr keeps the stack tight and the air gap uniform), stack factor (how much of the stack is steel versus air), and dimensional tolerance (which sets air-gap concentricity and therefore efficiency and noise). At Shree Balaji Electrical & Stamping we control all three under an ISO 9001 system, which is why our laminations run cooler, quieter and more efficiently.
Frequently Asked Questions
What is electrical stamping?
Why are motor cores made of many thin laminations instead of solid iron?
What materials are used for electrical stampings?
What makes a high-quality lamination?
What products need electrical stampings?
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