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Mu-metal for magnetic shielding?


Could someone please tell me where I could purchase mu-metal? I'm currently working on a project the requires a shield between two magnets. I'm also wondering if magnets are attracted to Mu-metal? Any help that you can give me would be greatly appreciated. Thanks.

Charles Tramble
- Fredericton, NB, Canada


Mu-metal is a common name for an 80% nickel, 4% molybdenum, 16% iron alloy with superbly high magnetic permeability. Carpenter Technology (a steel company) calls it HyPerm 80, and another name is Permendur. You can get it from CarTech, from Scientific Alloys in RI, probably from Specialty Steel & Forge: but your best bet for small quantities might be to do a web search using "magnetic shielding" as a topic.

It is strongly ferromagnetic, by the way. That's how it works- the field is held in the shield, away from the device you are trying to protect.

Good luck!

lee gearhart
Lee Gearhart
metallurgist - E. Aurora, New York

I want to know if the mu-metal products can absorb the attraction or repulsion of a motor device using magnets as "pistons" and "cylinder heads". The objective is to separate the magnets by blocking or absorbing the fields so motion can continue in rotation. You have probably worked with this already but if not, I am looking for output energy from rotation.

Michael Smith
hobbyist in energy field - South Bend, Indiana, US
September 1, 2008

I am not sure what you mean by shielding. Both magnets would be attracted to mu-metal. And still interact with each other.

Allen Storaasli
magnetics - Federal Way, Washington
November 22, 2008

Permendur is 48-50% Cobalt/Iron, with a 2% maximum allow of Vanadium (that's why Permendur 2V is also known as 49FeCo2V or FeCoV).
Hyperm 80 is a Nickel based alloy, like HyMu 80, the basic composition for MuMetal or MuShield is 75% Nickel, 15% Iron, plus balance copper and molybdenum.

Joshua Kimble
Metallography Tech - West Palm, Florida, USA
August 17, 2010

September 6, 2011

I'd like to get some information about mumetal.
Some mumetal has Copper and some has Mo instead. What is the difference??
Is the annealing procedure same for both the material??
Is it possible to coat resin or some inorganic substance on this material?
Please advise!

Yvonne Chen
- Taipei

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