Acal BFi kOr | Acal BFi UK

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Manufacturer's part number Product description Qty
Manufacturer's part number Product description Qty

Acal BFi kOr – consistent, high-quality amorphous and nanocrystalline cores

Acal BFi are a specialist provider of soft magnetic materials providing Fe-based amorphous and nanocrystalline cores through our kOr brand. We are committed to providing consistent and high-quality cores through a reliable materials base, stable production processes and rigorous testing from our in-house engineering team.

Acal BFi kOr's product range provides amorphous (kOr 156) and nanocrystalline (kOr 120) tape-wound cores in an extensive range of shapes and sizes. We can also customise and enhance designs for you. From concept to production, we design, test and manufacture amorphous and nanocrystalline cores to meet your specific application requirements.

Acal BFi kOr graph showing saturation vs permeability

Iron-based amorphous material has been developed as a contemporary replacement for electrical steel, especially in distribution transformers. Thanks to its small tape thickness and high saturation induction (1.56 T), it is possible to reduce losses as well as weight and dimensions, especially in low-frequency applications. This makes components high efficient both in purchasing and operational costs.


  • Low losses compared with silicon steel
  • Good linearity and frequency characteristics
  • Effective permeability (AL) and DC-tolerance adjustable with gap
  • Other size, shape or cuts (position, multi-cuts) available on request


  • Applicable ideally for transformers
  • Matches perfectly to standard bobbins
  • Adjustable to space limitations

Amorphous kOr 154

Iron-based nanocrystalline material with high saturation flux density (1.2 T), high Curie temperature (580℃) and low losses / high permeability up to 200kHz is the preferred choice for mid-frequency power applications and common mode chokes. Flat hysteresis loop with low remnant flux Br, high DC-tolerance, adjustable permeability between 30.000 and 100.000 (10 kHz) and near-zero magnetostriction complete the set of superior properties.


  • High-saturation flux density (1.2 T)
  • High curie temperature (580°C) and excellent temperature characteristics
  • Near-zero magnetostriction


  • Applicable for transformers and common mode chokes
  • Low losses allow high flux density at medium frequencies, ie reduced space
  • Standard sizes with adjustable permeability, ie tailored inductance and DC tolerance
  • Size and finishing can be customised easily, available also as cut cores

Nanocrystalline kOr 120

Customised shapes, cuts and dimensions

Amorphous and nanocrystalline cores are wound from ribbon (thickness about 20µm, width up to 50mm). Therefore we can offer many possibilities for customisation without significant tooling costs:

  • Any size and shape what can be wound onto a solid body. Bars and other parts can be cut off wound cores. Complicated or oversized shapes can be assembled from different parts.
  • Cores can be impregnated with epoxy for mechanical stability, especially before cutting.
  • Cores are to be protected by boxing into plastic or metallic cases, epoxy coating, wrapping with fibre tape, and/or lacquer.

Custom shapes

Custom Services for Magnetic Components

Our Custom Services for Magnetic Components (CSfMC) team support customers though every stage of their project, from design to production.

The team offer a complete service built on knowledge and expertise, designing and supplying a wide range of magnetic components including inductors, transformers and accessories.

Custom magnetic components

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