Consult the Magnet Doctor

Dr Ewan Goodier is Technical Manager at Eclipse Magnetics. He has worked extensively in magnetic system design and has a PhD in Electrical Machine Design and Permanent Magnets. Here, he answers some common magnetic questions (click on the question to see the answer).

Your Questions About Magnetics Answered Here By The Experts At Eclipse

What Are Magnets & What Is Magnetism?

What Permanent Magnetic Materials Are There?

How Do I Link A Magnet Polarity to Earth’s Magnetic Polarity?

Can I have a magnet with just one pole?

Field strength of magnets – does shape matter?

Magnet pull strengths, magnet field strengths

Magnet polarity marking – making identifying pole faces easier

Do you supply assemblies?

Can a magnet be demagnetised by applying an external magnetic field?

How can a magnet be designed to better resist an externally applied magnetic field?

Attraction or Repulsion – what is the rule?

What is Lenz’s Law?

What is Faraday’s Law?

Can I tap a thread into a magnet (so I can screw directly to it)?

Can I weld near magnets?

Longevity of magnets – how long will a permanent magnet stay magnetic?

Will a magnet affect my credit cards and other magnetic stripe cards?

Magnets with Pacemakers and Heart Defibrillators

Will a magnet affect my watch?

Will a magnet affect my cochlear implant (Hearing Aids)?

Will a magnet affect my USB data stick or compact flash memory cards?

Will a magnet affect my mobile phones or camera?

Will a magnet affect my hard drive?

What happens if radiation is applied to magnets?

Are Rare Earth magnets actually rare?

NdFeB magnets, Neodymium Iron Boron magnets, Neo magnets, Neodymium magnets, NIB magnets – are they the same thing?

What is a BH curve? What is Br? What is Hc? What is Hci? What is BHmax?

What should I consider relating to the safety of magnet usage?

Can we produce custom shape magnets for you?

Can we produce the stock magnet size but in a different grade?

Can I get a quotation for much higher quantities?

Can I buy magnets and magnetic assemblies in bulk?

I have an idea for a magnet design but I don’t know if it is possible – can you help?

I cannot find the information I am looking for – what can I do?