Laser Cutting vs. Stamping – Technology and process expertise make the difference

A precise overview

In the production of electric machines and stators, electrical steel laminations play a central role: their magnetic properties largely determine core losses, efficiency, and performance. Two common manufacturing methods are mechanical stamping (or shearing/guillotine cutting) and laser cutting. You’ll often hear: “Laser cutting is bad for magnetics.” But that’s an oversimplification — not every laser, and certainly not every parameter set, is the same. At TEPROSA, we use fiber lasers and optimized cutting parameters — and that makes all the difference.

In this article, we look at:

1. What happens during stamping?
2. What happens during laser cutting — especially with a fiber laser?
3. Where are the key differences?
4. Which advantages can laser cutting offer under the right conditions?
5. What should you look for in a supplier/partner — and what does that mean at TEPROSA?

1) Stamping — what happens during mechanical cutting

With stamping or guillotining, electrical steel is separated by mechanical force. Typical effects include:

• Plastic deformation at the cut edge (roll-over, shear zone, fracture zone) and potentially burrs.
• The induced mechanical stresses and micro-deformations restrict domain-wall motion in the ferromagnetic material, which increases hysteresis (iron) losses.
• Burrs, uneven edges, or poorly executed contours can impair stacking quality; tiny air gaps may arise between laminations, which can in turn elevate eddy-current and stray losses.
• Strengths of stamping: extremely economical at very high volumes with stable geometry and well-maintained tooling.
• Trade-offs: less flexibility for geometry changes; tools must be engineered and maintained; and with very high-grade steels (e.g., thinner laminations or high-silicon materials), the edge-affected zone is typically more sensitive.

Bottom line: stamping is a proven industrial process — but depending on material, tool condition, and geometry, it can measurably influence magnetic properties.

2) Laser cutting — especially with a fiber laser — and what really matters

What happens during laser cutting?

• The laser separates material by melting, evaporation, or ablation. When cutting electrical steel, a heat-affected zone (HAZ) can form, where microstructure, residual stress, and crystallographic texture may change.
• Results depend strongly on laser source, cutting speed, assist gas, focus diameter, and material thickness. Some studies report degradation at low induction levels — but also show that laser cutting can outperform mechanical shearing at higher induction, depending on parameters and evaluation criteria.
• Many negative statements about laser cutting are based on CO₂ lasers. That doesn’t automatically apply to fiber lasers — and certainly not to fiber lasers with optimized parameters.

Why the laser source (fiber vs. CO₂) matters

• CO₂ lasers operate at ~10 µm; fiber lasers at ~1 µm. The shorter wavelength typically enables smaller focus spots, better absorption, and lower thermal load for the same cutting task.
• Fiber lasers can achieve narrow kerfs, high contour accuracy, and a smaller thermal edge zone — potentially less impact on magnetic properties.
• Misapplied parameters (too much heat input, wrong assist gas, poor focus, too slow speed) can still produce a sizable HAZ — which is why process expertise is decisive.

Typical mistakes to avoid in laser cutting

• Excessive heat input → larger HAZ → altered microstructure → higher hysteresis losses.
• Wrong assist gas or gas guidance → oxidation/impurities → poorer edge quality.
• Sub-optimal focus or too low cutting speed → too much energy per unit length.
• Parameters not adapted to thickness, alloy, or lamination texture → avoidable quality losses.

Takeaway: With a fiber laser and optimized parameters, the loss in magnetic quality can be minimal — and in certain operating ranges laser-cut parts can perform on par with or better than mechanically sheared parts.

3) The differences — stamping vs. laser cutting at a glance

Core message: A blanket statement like “laser cutting is always worse for magnetics” is misleading. Laser type, parameters, and process control are decisive.

4) Why laser cutting can offer real advantages — and why TEPROSA makes them count

As a partner focused on electrical-steel manufacturing, we want to highlight the real-world advantages of laser cutting — provided it’s done right:

• High design & manufacturing flexibility: Ideal for custom laminations, variants, prototypes, and small to medium lot sizes. Fiber lasers enable rapid reprogramming, no tool changes, and high variant diversity.
• Save tooling cost, accelerate time-to-market: No lengthy tool development — perfect for prototypes and ramp-ups.
• Excellent edge quality (with the right process): Less burr, smaller affected zones, better stackability — reducing air gaps and helping to keep eddy-current losses low.
• Magnetic quality can be comparable — or better: Under optimized parameters, the magnetic impact of laser cutting can be lower than mechanical shearing in certain induction/frequency ranges.
• State-of-the-art fiber lasers: Smaller HAZ, precise cutting, and stable focus control directly support magnetic performance.
• Great for thin laminations and specialty grades: At typical electrical-steel thicknesses (e.g., 0.20–0.35 mm) and high-Si grades, the benefit of a well-tuned laser process becomes very clear (no shearing deformation).
• Process development as a service: Because TEPROSA uses fiber lasers only and tunes parameters specifically for electrical steel, we can meet stringent magnetic-quality targets rather than offering a one-size-fits-all laser job.

Staying realistic
A poorly parameterized laser process can impair magnetics more than a well-executed stamping process. That’s exactly why technology choice and process competence both matter — laser type, focus, speed, assist gas, validation, and deep material know-how.

5) Choosing the right partner (e.g., TEPROSA): what to look for

If you want to ensure your supplier is truly qualified for electrical-steel laser cutting, we recommend checking:

1. Laser type — fiber vs. CO₂: Make sure a modern fiber-laser system is used (shorter wavelength, better absorption, smaller HAZ).
2. Parameter customization: Are cutting speed, focus, assist gas, thickness, alloy, and heat input tailored to your grade and geometry? Is process development documented?
3. Material expertise: High-Si grades and thin gauges are sensitive to cutting influences. Your supplier should have proven experience with these materials.
4. Quality validation — magnetics & edges: Does the partner check magnetic quality post-cut? Are there data on iron-loss impact, burr height, and stacking quality?
5. Customer references / series experience: Are there successful motor/generator use cases?
6. Flexible lot sizes & variants: Can new geometries be implemented quickly? Is there a cost model that works for small/medium lots?
7. Cost–benefit clarity: At very high volumes, stamping can remain the most economical; for variant-rich mid volumes, laser cutting often wins.
8. Process transparency: How are measurements done, and which standards (e.g., IEC 60404 for magnetic testing) are applied?

As a TEPROSA customer, you benefit from exactly this approach: fiber lasers only, parameters optimized specifically for electrical steel, magnetic-property checks, and the flexibility you need for geometry and batch size.

6) Conclusion

For electrical-steel laminations, the manufacturing process decisively affects magnetic performance. Stamping is proven and powerful — yet limited when it comes to design freedom, variant production, or premium electrical-steel grades.

Laser cutting — especially with a fiber laser and optimized parameters — can achieve magnetic quality that is equivalent to, or even better than, standard stamping when the process is dialed in. That’s where TEPROSA focuses: choosing the right laser, setting the right parameters, and validating edge and magnetic quality — so your laminations meet their targets.

If you’re looking for a partner who doesn’t just “offer laser cutting,” but delivers laser cutting with deep electrical-steel competence, TEPROSA is your team. Get in touch — we’ll show you how we meet your requirements while safeguarding the magnetic quality of your laminations.

M. Barth

TEPROSA GmbH, Paul-Ecke-Strasse 6, 39114 Magdeburg, Germany

Geschäftsführer & Gesellschafter der TEPROSA GmbH.