Sigint Solutions


NMF25 Mu-metal foil

 nmf25 mu-metal foil
NMF25 is a Mu-metal foil for shielding of low-frequency magnetic fields. Due to the low electrical resistance even for shielding low-frequency electric fields (LF) and high-frequency electromagnetic fields (HF).

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Area of Application
For small areas by using a double sided adhesive tape or for large-surface applications with glue. Can easily be bent and folded and be cut with scissors or a knife.

Corrosion resistance

Good corrosion resistance in a normal environment.

Attenuation for low frequency sources of electric and magnetic fields, depending on application in one layer, is 14dB (shielding effectiveness of  80%). For high frequency sources of electric and magnetic fields the attenuation in one layer is 100dB The shielding attenuation is regularly tested by Professor Dipl.Ing. Pauli at the University of the German Federal Armed Forces in Munich due to the standards ASTM D4935-10 and/or IEEE-STD-299-2006. The expert reports are available upon request.

shielding-graph-nmf25-lf shielding-graph-nmf25-hf

Technical Data

  • Width: 25 cm
  • Length: By the meter / 50 m roll
  • Attenuation LF magnetic field: 14 dB (80 % shielding); for more shielding use multiple layers!
  • Attenuation HF: 100 dB at 1 GHz
  • Saturation flux density: 0.8 T
  • Weight: 900 g/m²
  • Material thickness: 0.1 mm
  • Color: Silver
  • Materials: Alloy of nickel, iron, molybdenum
  • Surface conductivity: 0.004 ohm (square resistance)


Material Application

In the case of processing in electronic applications, standard double sided adhesive tapes can be used for bonding on the surface. For walls, ceilings and floors (for shielding cables or fuse boxes) use viscous glue with high adhesive strength. The strips of the foil should be overlapped at least 1 cm. Fuse boxes should be shielded with at least 2 x 2m! After drying, NMF25 can be painted over with commercial diespersion paint.

Due to the highly conductive surface this material can be contacted and grounded easy to shield low frequency (LF) electric fields. For professional grounding we recommend our grounding strap EB in combination with our grouding set ES.