Iron Core

Manufacture of iron cores

TEPROSA is a specialist in the manufacture of iron cores made of electrical sheet (electrical steel strip) for the construction of magnetic cores of electrical systems. Common applications are transformers, relays, transformers or chokes. For the use in prototyping, or in small series, the production of the iron core by laser cutting is particularly suitable because of the flexibility, speed and economy.

With our cutting systems, we manufacture common cores (M-, E-, ED-, EE-, EI-core) in sheet thicknesses of 0.1-0.65 mm with the highest quality and tight tolerances up to a maximum diameter of 1,000 mm.

Laser Cutting of Iron Core – Fast, Precise and Economical

Iron cores (also available as sheet packages) are made of electrical steel, a special iron-silicon alloy. Due to its special properties, the use of laminations made of electrical steel strip for the production of cores leads to a significantly improved energy efficiency of electrical systems and thus to a sustainable use of resources.

Different cold-rolled strips are classified into grain-oriented and non-grain-oriented materials according to their properties. TEPROSA manufactures laser-cut sheet lamellas, as well as finished sheet packages for prototypes and small series.

The advantages of laser cutting with regard to core manufacturing are found particularly in its cost-effectiveness, in addition to the flexibility of the process. Since laser cutting does not incur tooling costs and setup costs are low, production is cost-efficient even for very small quantities.

The precise laser beam guidance, the high power density and a high cutting speed enable highly precise contour accuracies of ± 0.01 mm, exact, almost right-angled cut edges and clean cut surfaces when using the appropriate cutting gases. Depending on the material thickness, narrow kerfs of 0.03 mm are also possible. Furthermore, in contrast to alternative cutting processes such as punching, only very minor structural changes occur at the cutting edges during laser cutting.

Your supplier for magnetical cores

TEPROSA GmbH has specialized for many years in the manufacture of sophisticated, precision-fit laser parts of exceptionally high quality. In the field of electrical sheet, we manufacture individual iron cores, sheets for stators and rotors, as well as entire sheet packages (stator or rotor packages) from various steel grades. We process grain oriented electrical steel for generators, transformers and other electrical machines.

Coatings for insulation

In order to prevent the short circuits between the laminations in electrical steel stacks and thus reduce the eddy currents, various coatings are applied to the strip. The coating thicknesses vary from 1 to 4 µm. Depending on the processing technology and subsequent application, coatings exist for better corrosion protection, improved insulation of the individual layers, heat resistance, improved punching properties or weldability.

• Coating C3 – improvement of the lubricating effect. Relevant, for example, for the stamping process.
• Coating C4 – Coating to improve corrosion protection and insulation resistance.
• Coating C5 – Optimization of temperature resistance. Relevant e.g. for stress relieving after the stamping process.
• Coating C6 – Coating for a particularly high insulation resistance.
• Backcoat – coating as a bonding technology for sheet packs and iron cores.