Get a quote

In 3 steps to your individual offer for Backlack

Select the type of electrical steel and the quantity. If you already have a technical drawing, attach it right away. Then all we need is your contact details and we will send you an individual offer for your electrical sheets coated with baking varnish! If you need several different slat geometries, you can simply submit the order form several times.

1. Choose your material
2. Upload technical drawing
3. Provide contact details

Phone: 0049 (0)391 598184 70


» Electrical steel with Backlack coating

Electrical steel coated with Backlack consists of an iron-silicon alloy and is divided into grain-oriented and non-grain-oriented material. The starting material is manufactured as cold strip and then painted with baking varnish. It has special physical properties and is one of the soft magnetic materials. Non-grain-oriented electrical steel is classified by DIN EN 10106. There are a variety of standard grades for use in electrical systems, motors and machines. Here you will find an overview of the materials we process at TEPROSA:

  • M235-35A
  • M270-35A
  • M330-35A
  • M270-50A
  • M330-50A
  • M530-50A
  • M400-50A
  • M800-50A
  • NO20-15
  • other types of electrical steel on request
» Manufacturing conditions for Backlack

Our manufacturing conditions for laser cutting

  • Minimum kerf width/minimum spot diameter: 0.03 mm*
  • Repeat accuracy ±2µm
  • Micro-bridges from 0.03 mm (small connection between contour and sheet to anchor the blanks in the sheet composite)
  • Cutting speeds up to 50mm/s
  • Cutting gas support up to 25 bar
    • Nitrogen
    • Oxygen
  • Contour accuracy: ± 0.01 mm*

*Depending on the material/material and its thickness.

» Individual production & materials

Can’t find your material in our overview? We are also happy to process materials provided by you or procure appropriate materials. Upon request, you can receive all materials with the corresponding material test certificate.

» Information for buyers

We specialize in business-2-business business. Upon your request, you will immediately receive a written offer that takes all technical requirements into account. Here you will find further links and helpful information for buyers:

» Inquiry without CAD data

We would be happy to create the data for you! Simply send us a corresponding drawing or the geometric data of your laser part. Our experts will then contact you immediately.

» Confidentiality & data security

We guarantee the security of your data – if you still need a confidentiality agreement in advance, you can download our confidentiality form >here. We would also be happy to check your in-house agreement. Please simply send this to us by email to:

We take confidentiality and data security very seriously! If you would like to conclude a non-disclosure agreement, send us your form or download our template.

Elektroblech Laserschneiden Statorblech Lamelle TEPROSA
Elektroblech Laserschneiden Statorblech Lamelle TEPROSA
Elektroblech Laserschneiden Statorblech Lamelle TEPROSA

The Backlacktechnology

Stacking of laser-cut electrical sheet metal lamellas using Backlack-technology

Baking varnish is a special joining technology for sheet metal packages. After the individual lamellas have been cut, electrical steel with a baking varnish coating is baked into a sheet metal package in a two-stage temperature step. The result is a full-surface, solid connection between the individual sheets with complete insulation. Sheet metal packages manufactured in this way have high precision and perfect magnetic properties.

Advantages of the Backlack process:

The Backlack process offers several advantages over alternative packaging processes, which we will discuss in detail below.

  • Precision – Sheets coated with baking varnish are baked over the entire surface. This means that even delicate slats can be assembled precisely.
  • Freedom of design – Baking varnish allows for optimal design of the slats/sheet metal stacks, as no stacking knobs or weld seams have to be taken into account.
  • Insulation – In contrast to other packaging techniques, no short circuits occur when packaging with baking varnish.
    Magnetic properties – No other process leaves the magnetic properties of electrical steel as untouched as the baking varnish process.
  • Connection – The full-surface connection of the individual slats reduces vibrations.
    Thermal conductivity – Electrical sheet metal packages with a baking varnish coating have improved thermal conductivity.
  • Stability – Thanks to the full-surface connection, baking varnish packages are very stable and robust.

Backlack for stacking laminated cores

We manufacture electrical sheet metal lamellas coated with baking varnish for the construction of magnetic cores in the form of rotors, stators or transformers. We use the latest fiber lasers to produce the sheet metal slats. We cut stator and rotor sheets up to a maximum diameter of 1,000 mm. Our laser-cut sheet metal slats meet the highest quality and tolerance requirements and are particularly suitable for the production of prototypes and in the production of small series (1-10,000 individual slats).

Backlack – not just for prototypes and samples

Although Backlack technology has long been considered a prototype technology, series components for small and medium quantities are increasingly being manufactured using baking varnish. The optimal design and corresponding production of electrical sheet metal packages with sophisticated geometries with the highest precision and accuracy is becoming increasingly important and makes baking varnish socially acceptable for series production. In combination with a modern laser processing center and industrial high-performance ovens, surprisingly large quantities can be produced at an economical price. Please feel free to contact us if you would like to find out more about whether baking varnish technology is suitable for the production of your product.

Your partner for Backlack

TEPROSA GmbH has specialized in the production of sophisticated, precisely fitting laser parts of exceptionally high quality for many years. In the area of ​​electrical sheet metal, we produce individual sheet metal lamellas and sheets for stators and rotors, as well as entire sheet metal packages (stator or rotor packages) made of various types of steel. We process grain-oriented electrical steel for generators, transformers and other electrical machines. We use the baking varnish process to package the sheet metal packages. As a long-standing supplier to various OEMs, the quality of our work is particularly important to us. We therefore work according to uniform processes and thus ensure consistent quality and complete traceability of each individual production step.

Backlack and other coatings for insulation

In order to prevent short circuits between the lamellae in electrical laminations and thereby reduce eddy currents, various coatings are applied to the strip. In addition to the option of coating electrical steel with baking varnish, there are other insulation coatings. The layer thicknesses vary from 1 to 4 µm. Depending on the processing technology and subsequent application, there are coatings for better corrosion protection, for improved insulation of the individual layers, for heat resistance, for improving punching properties or for weldability.

  • Backlack – Backlack process; Coating as a joining technology for sheet metal packages.
  • Coating C3 – Coating to improve the lubricating effect. Relevant e.g. for the punching process.
  • Coating C4 – Coating to improve corrosion protection and insulation resistance.
  • Coating C5 – Coating to optimize temperature resistance. Relevant, for example, for stress-relieving annealing after the stamping process.
  • Coating C6 – Coating for particularly high insulation resistance.
Teprosa – technology + Engineering

Paul-Ecke-Str. 6
39114 Magdeburg

Tel 0391 598184 70