The 4 Types of Permanent Magnets.
Selling magnets in a magnet shop all day is pretty boring. Hence why we also sell Blacksmith Supplies! However, what a lot of people don’t know is that magnets are not just magnets. There are loads of different types. All are very different with their own set of characteristics.
If you are looking to use a magnet for DIY & home improvements, a school science project or an electrical project of some kind. Then it would be beneficial to know the best magnet for each job.
First, it might be prudent to know that there is a subsection of magnet that you should be aware of. That been the electromagnet. An electromagnet works when a current of electricity passes through it and can be turned on and off. Whereas, of course, a permanent magnet keeps its magnetism.
However, in this blog, I think I better just concentrate on the permanent sort. Stop it getting too complicated and boring… too late?
The main types of permanent magnet are:
- Neodymium iron boron (NdFeB)
- Samarium cobalt (SmCo)
- Ceramic or ferrite magnets
These are the main types and the ones we just so happen to sell here at Magnetics.net.au in Brisbane. Details of where to find us, if you don’t fancy buying online, can be found here
More often called neodymium they are made from a rare earth metal that is put through an extensive process and magnetised. These are the most common of the Rare Earth Magnets and certainly, have the most power of the four permanent magnets. This type of magnet will take some hammer, in both heat and cold. In fact, neodymium is highly resistant to demagnetization. Making them ideal for industrial usage.
One drawback about this magnet is that they are predominantly made from Iron. So will rust when out in the elements over time. Very susceptible to oxidization. Which makes them pretty brittle if left outside.
SmCo (Samarium Cobalt) Magnets
Quick quiz; which came first Samarium cobalt or neodymium? Well, SmCo of course! These babies are another powerful magnet. And were created in the 1970s, just before the creation of the NdFeB. The positives of the SmCo over its baby brother is that they don’t corrode as easy. Making them ideal for marine and medical purposes. As well as having a better temperature resistance.
Like me, they retain their magnetism, certainly, at high temperatures. However, they are slightly less powerful than neodymium magnets. And when it came to industrial uses, much more expensive.
Alnico is actually an acronym, which refers to a family of iron alloys. In addition to iron, they are also composed primarily of aluminium (Al), nickel (Ni) and cobalt (Co), hence the highly creative name; al-ni-co. However, Alnico magnets are not as popular as other types of magnets. Therefore, they have become a bit expensive. And, have been replaced by the cheaper neodymium.
No matter, these magnets are designated ferromagnetic. Which means they have a high coactivity. In other words, resistance to loss of magnetism. Therefore, they are actually used to make other permanent magnets. They can be used in basic applications like fridge holders. But, as previously stated, it can be hard to find them.
Magnets, Ceramic or Ferrite?
If you are looking for a basic craft magnet then look no further than the Ceramics. These are another commonly used type of magnet for low-level applications like holding paper up. Pretty cheap to make and acquire. But you wouldn’t want to use them for anything you need a strong Neodymium for. Like holding up something heavy. Use these for basic crafts, fridge magnets, or holding lightweight items. You know, like your daughter’s daddy picture!
They should be used as a cost-effective option. However, a good point to note; the high coercivity means the materials are extremely resistant to becoming demagnetized. Which is an essential characteristic for a permanent magnet. And pretty good for holding on to shopping lists on the fridge!
Speak With The Best Magnets Supplier In Australia
At Sekao Engineering we make sure that you get the best quality. We do this by testing everything we sell ourselves, in our own workshop. Knowing the different types and their strengths and weaknesses can help you choose the right ones in your projects.
But, we are also here to help you decide. If you have questions about which products to use in a specific project, contact Alan in the workshop. Call us, the number is above. Or just come round and see for yourself.