Are stronger magnets better magnets?
You may be aware that the strongest magnets commercially available are rare earth Neodymium magnets… You can shop our range here!
These are made from an alloy of neodymium, iron and boron; also known as NdFeb Magnets, and are available in a range of grades, the strongest being N55 – But is this the best magnet for your project?
Here at MagDev, we often get asked the question: ‘Is a stronger magnet a better magnet?’.
As the saying goes, if you’re using a magnet to hold or attract something, then two poles are always better than one. But beware… the flux of a stronger magnet can travel a shorter distance, and you’ll therefore need to keep the air gap between the magnet and your surface as small as possible.
There are many factors to consider in magnetic design, and strength is only one of them. In answer to our customers’ question - Stronger does not necessarily mean that a magnet is better.
With all magnets, there is what is referred to as a ‘window of effectiveness’. This means that a stronger magnet can be too strong to have an effect, and of course, a weaker magnet can be too weak to have an effect also.
We’d recommend taking time at the beginning of your project to identify the right magnet to suit your requirements, ultimately saving you time and expense.
With this in mind, what variables must you consider when selecting the best magnet for your project?
It is first important to consider the surface of your contact steel.
Ask yourself - Is the surface rough and rusty, or flat and machined? Is the surface area an irregular shape? Each of these factors will have an impact on the pull of your magnet.
If the contact steel is rusty, painted or uneven, then the resulting gap between the magnet and the contact steel will lead to a reduced ‘pull’ from the magnet. As the gap increases, the pull decreases, using an inverse square law relationship.
When reviewing your options, it is important to consider the temperature that you’ll be expecting your magnet to operate at. If the temperature of a magnet exceeds its maximum operating temperature, it will lose its magnetism.
While samarium cobalt magnets are not quite as strong as neodymium magnets, they have a far higher operating temperature of up to 500 degrees Celsius.
Watch the video as Assistant Sales Manager, Alex Tremlett, answers the frequently asked question: ‘Is a stronger magnet a better magnet?’.