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magnetic field from a permanant magnet can it be blocked? Answered

Original Question (Hi does anyone know of a material that will block the magnet field from a permenant magnet without the material being to thick.)

Thanks for your replies, to go into more detail, the material must not be attracted to the magnet as would mild steel
The magnet force/pull is about 1LB and I need a material less than 5mm thick that will reduce its pull by at least 10 percent but the higher the better.
Also it must not cost a fortune, (How much does Mumetal cost and is it attracted to a magnetic force),  I have searched high and low and I am now begining to think that  my search is futile and maybe no such material has yet been discovered. Your my last hope people. Thank you.



Thanks to everyone who replied.

Mild steel will "block" it to a large extent.

Define shielding effectiveness.

Mumetal is fantastic stuff, but, after bending, requires hydrogen annealing to re-set its properties.


Mumetal is rediculasly expensive on eBay.
That annealing to re-set its properties is most interesting.
Do you know what is it ( grain oriented ) ??


Hmm. I suppose it must orient the metals grains, to increase the freedom of magnetic domains to align with the applied field. Its GREAT stuff for highperformance signal transformers too.


Yes excellent stuff.
I have hand wound wire ( on / through ) a tape wound toroid of such
grain oriented material which had a narrow very square B-H curve.
I believe that was useful to make an excellent low loss up inverter.
Though I don't remember its permeability.


. Almost any ferrous/magnetic material will do a reasonable job. Hard disk drives have very powerful magnets to position the head(s) and the shielding they have is quite thin, light, and effective.

YES - No - Depends.  Your question is a bit vague.

Mu metal blocks magnetic fields - sort of.