Silicon-Iron (Si-Fe) 

The entire O.M.E.M. product range is available in grain-oriented Silicon-Iron, in different material thicknesses and magnetic qualities: 0.23mm – 0.27mm – 0.30 mm – 0.10 mm – 0.05 mm and non-grain oriented 0.35mm – 0.5mm Silicon-Iron.

The Silicon-Iron cores are offered in different material qualities – from M5 magnetic laminations to high permeability magnetic laminations (HIB- M0) and are offered and manufactured according to the test values recommended by O.M.E.M. or agreed with customers to meet their requirements. The technical info section shows all the tables listing the magnetic values guaranteed for these materials.

OMEM-tabfesi1 pdf

Silicon-Iron Toroidal Cores

 O.M.E.M.  manufactures Silicon-Iron toroidal cores with a minimum inside diameter of 10mm up to a maximum outside diameter of 1500mm and with a strip height ranging from a minimum of 5mm to a maximum of 500mm. The weight of these toroidal cores ranges from a few grams to over 500kg.

O.M.E.M. manufactures this product with a square, rectangular or stepped cross-section.

Hybrid Cores

O.M.E.M.  manufactures hybrid toroidal cores, with or without cuts, made of Silicon-Iron, Nickel-Iron or Nanocrystalline material


Silicon-Iron cut cores.

Many applications require cores with one or multiple cuts, both to fit pre-made copper coils, for example C or three-phase cores, and to fit air-gaps for inductors or other applications.

Silicon-Iron cut toroidal cores

Toroidal cores can be cut according to customers’ requirements with a number of cuts ranging from 2 to 48. Cores with a single cut can also be manufactured for special applications.

The cut cores can be supplied with non magnetic steel straps closed with an hexagonal nut, a pawl or a non magnetic steel strap with seal.

On request, O.M.E.M. supplies cores with air-gaps fitted and calibrated according to the requirements of the electric test supplied by the customer.


“C”, three-phase and specially shaped cores 

O.M.E.M. manufactures Silicon-Iron “C” and three-phase cores of standard or custom sizes, with a weight ranging from a few tenths of grams up to over 500kg. The “C” shaped and three-phase cores are manufactured with a strip up to 500mm high, with 2 or more cuts, and with a square, rectangular or stepped cross-section.

For specially shaped cut cores, our Technical Department can find the best mechanical and magnetic solution by liaising with our customers.

The cut cores can be supplied with non magnetic steel straps closed with an hexagonal nut, a pawl and, if required, with air-gaps.

I nuclei tagliati possono essere forniti con fascette di acciaio amagnetico con chiusura a dado esagonale o a nottolino ed eventuali traferri.


Specially shaped cores

O.M.E.M. can manufacture cores of any shape from bespoke designs: oval, stepped, rectangular or “D” shaped. By contacting our Technical Department, special shapes can be manufactured.


O.M.E.M. manufactures custom designed Silicon-Iron armatures for solenoid valves.

Tolerances and magnetic values for specially shaped cores and armatures must be agreed beforehand.