Magnet FAQs

Yes, please feel free to telephone 0144 287 5081 and ask to speak to someone in technical sales. Our friendly staff are trained engineers with extensive product and application knowledge and they are waiting for your call anytime between 08.30 and 17.00.

There are actually many ways in which you can determine the strength of a magnet:

• Maximum Energy Product – Measured in Mega Gauss Oersteds (MGOe), the higher the Maximum Energy Product the greater the magnetic field of the magnet.
• Coercivity – Measured in Oersteds (Oe), measures the resistance of a magnetic material to demagnetisation.
• Remanence – Measured in Gauss is the residual magnetism left behind in a ferromagnetic material after magnetisation. The higher the value the stronger the magnet.
• Pull Strength – Measured in kilograms is one of the easiest ways to compare the strengths of various magnets. It is quite simply the force required to separate the face of the magnet from a perfectly flat, steel surface.

If a magnet is fully magnetised then you will not be able to make it stronger as it has reached a saturation point.

Stacking magnets on top of each other will effectively create a bigger magnet with more performance.

Only in examples where magnets have been demagnetised could you ever increase their strength.

Yes, they can which is why it is important to source the right magnet for your application.  Here are some of the ways in which magnets can lose their magnetism:

• Heat – Magnets will lose their magnetism if they are exposed to heats above a point known as the Curie temperature. Different types of magnets offer hugely different operating temperatures.
• Demagnetising Magnetic Field – the Coercivity of a magnet is its ability to withstand being demagnetised by an applied magnetic field. This could be from another magnet or a solenoid.  Neodymium and Samarium Cobalt magnets have a high coercivity and therefore will demagnetise less easily than Alnico or Ferrite magnets for example.
• Shock – Mainly seen in Alnico Magnets, these magnets can be easily demagnetised if dropped or hit with a hammer as the energy is transmitted through it.

In theory yes they do however if they are not exposed to conditions that may demagnetise them magnets will keep their strength for a long time. A Samarium Cobalt (SmCo) magnet will take approximately 700 years to lose half its strength for example.

Magnetic Force obeys an Inverse Square Law with distance which can be a little complex to follow but here are some simple examples based on moving the distance between two magnets:

• Distance Doubled | Force is now a quarter the original value
• Distance Halved | Force is now four times the original value
• Distance increased by five times | Force is now one twenty-fifth the original value

Ferromagnetic Metals are the single most group of metals that are attracted to magnets.  Some of the more common ferromagnetic metals include iron, nickel, cobalt, but also alloys that contain ferromagnetic metals – steel being an obvious example.

In order for a magnet to deliver its optimum performance then it requires conditions.  In real-world applications this very rarely happens so here are the things to look out for that will affect a magnet's performance:

• Air Gaps – This is the introduction of any non-magnetic material between the face of the magnet and another magnet or ferrous object. This can literally be a gap of air in some instances but also think about painted, rusty, dirty and uneven surfaces.
• Material Thickness – If you are applying a magnet to a steel surface then the thickness of the steel needs to be thick enough to absorb all the magnetism. If you apply a strong magnet to a piece of think steel sheet for example it will not clamp firmly as the majority of the magnetism is not absorbed.
• Material – Mild Steel is the perfect material for a magnet to attract to. Other metals although magnetic have a lesser ability to conduct magnetism.
• Temperature – Exposing a magnet to temperatures above its operating limit will cause it to permanently lose performance. Neodymium in its most standard form must not exceed 80°C for example.
• Corrosion – It a magnet is used in outdoor applications there is a possibility that its coating may become damaged which will expose the magnet and cause it to corrode which will result in a loss of performance. Samarium Cobalt and Ferrite magnets are both perfect for outdoor applications as they do not corrode.
• Sheer Force – When a magnet is fixed to a surface in a vertical position its performance will be approximately 1/5^th of its stated performance therefore a magnetic with a higher pull force may be required. However, rubber-coated magnets increase friction levels and make a significant difference in this application.

Our advice is always to keep magnets away from any electrical or electronic device as a general rule as you never know what is inside each and every device.

Magnetics has historically been linked to damaging storage devices based on magnetic storage which can include a credit card strip, a hard drive, a floppy disc etc…  However, most phones and tablets use non-magnetic storage today so this is no longer the issue it once was.

Newer devices do contain critical components that can be sensitive to magnetism.  It is likely that you would need to expose it to the field of a very strong magnet but none the less there is a risk of damage.

Yes, the main risk to humans lies in the misuse of magnets.

We see for sale on the internet incredibly large neodymium magnets that are sold to the general public.  These magnets are incredibly dangerous and can cause horrific injuries … nothing can prepare you for the devastation caused by two of these magnets attracting each other unexpectedly.  This is why we do not sell magnets above a certain size to the general public.

If part of your body is caught between two attractive magnets then pinch injuries can be caused, the stronger the magnets the worst the injuries will be.

As small neodymium magnets have been more widely available they can easily get into the wrong hands including children.  If swallowed these magnets can cause life-threatening injury and will require surgery to be removed.

Heart pacemakers are also adversely affected by magnets and wears of such should not come into contact with magnets.

For more health and safety advice you can consult our dedicated document here https://e-magnetsuk.com/health-and-safety-pdf/

Ferrofluid is a very special liquid that is magnetised when brought into the presence of a magnetic field.  The Ferrofluid created wild, spikey shapes and patterns as it is in close proximity to a magnet. Most pictures of Ferrofluid depict it with a very ‘spikey’ shape which is caused as the ferrofluid forms the most stable shape it can to minimise the total energy of the system, this is known as normal-field instability.

Provided that the material has not been damaged by extreme heat, the magnet can be re-magnetized back to its original strength.

Magnets can be a very useful thing to have around but there are many applications that rely on magnets that have become part of our daily lives, some of them may surprise you...

• Computers
• Speakers
• Radios
• Televisions
• Food processing to make sure our food is safe
• Wind Power generators
• MRI Scanners
• Mobile phones
• Credit Cards
• Vacuum Cleaners
• Washing Machines
• Electric Cars
• Anything with an electric motor...the list goes on and on...

Magnets are used throughout the home but most of the time you don’t even know they are there.  Some uses are more critical than others but here is a selection of the popular items that use magnets in the home:

• Electric Cars
• Burglar Alarm
• Cat Flap
• Telephone
• Smart Phone
• Computers
• Speakers
• Cupboard doors
• Microwave oven
• Mixer
• Vacuum cleaner
• Therapy magnets
• Handbag clasps
• Doorstops etc...

The type of glue required will very much depend on the strength of the magnet and the surface you are wanting to adhere it to.  Strong adhesives are generally required such as two-part epoxies and cyanoacrylates (super glues).  We stock two different cyanoacrylates, one for use on Wood and Paper and the for use on Metals.

No...you should never attempt to cut or drill a magnet.  Most magnets are very brittle once they emerge from the manufacturing process and any attempt to cut or drill the magnet will inevitably cause it to break.

If you require a very specific size of magnet or require a magnet with a hole or holes then please contact us as we can produce magnets to your exact specifications for low costs and low volumes.

Yes, however, the reality of it happening during normal day to day life is quite rare.

Credit cards incorporate a magnetic substance that forms the ‘magnetic strip’ on the card.  This is then covered by a thin but very tough and durable film of plastic.  Most magnets we encounter during the day are not even visible and are built into devices such as smartphones, tablets, speakers etc...and so your credit card would not get close enough to the magnet and the magnet would not probably be strong enough to cause an issue.

If you were having an MRI scan or were handling large, powerful magnets then, naturally you would ensure your credit card was out of the way.

Although the risk not high we would always recommend keeping your credit card away from magnets as ultimately, they can be damaged by magnets.

Yes and in actual fact Bunting- eMagnets and Bunting Magnetics Europe are part of SUSMAGPRO which is a European, EU funded project which has a primary focus on Sustainable Recovery, Re-Processing and Reuse of Rare Earth Magnets.  The project hopes to be marketing recycled magnets very soon.

You can learn more about SUSMAGPRO here.

Making your own Fridge Magnets is great fun and really is a low-cost activity.

We have 3 different types of magnets that lend themselves perfectly for this application:

• Ferrite Disc Magnets – Low cost with a reasonable holding force. Simply glue in place.
• Flexible Magnetic Rubber – Low Cost and extremely versatile. Flexible rubber is available in sheets for you to cut to size, pre-determined kiss cut shapes to save you time and these can be either glued in place or can be purchased with self-adhesive backing.
• Neodymium Disc Magnets – This is the magnet if your design requires a small but powerful magnet. They are available in a vast array of sizes and strengths and can be simply glued in place.  They are also available with self-adhesive backing.

There are many magnets available that are dedicated for use on wipe boards, whiteboards and dry-wipe boards.

Typically, ferrite notice board magnets are very popular due to their low cost, bright colours, good strength and ease of handling.

These magnets can come in a vast range of sizes and shapes allowing you to select the perfect magnet for your requirements.  Neodymium variations are also available for applications where a great force is required.

Flexible magnetic rubber is also a good option.  These can be purchased in a larger number of different shapes, sizes and colours including squares and circles which are perfect for planning boards.  Flexible magnetic rubber grid lines are also available in a number of colours and thicknesses which again are perfect for creating planning boards.