A Complete Guide to Rare Earth Magnets

What Is a Rare Earth Magnet?

A rare earth magnet is a magnet made from one of the rare earth elements (of which there are 17) in the Lanthanide series of metals in the periodic table. The two most common rare earth magnets are Neodymium (Nd-Fe-B) and Samarium Cobalt (SmCo). Read more about these two types of magnets.

For more information, please visit our website.

The term “rare earth” can be misleading, because rare earth metals are not very rare. They’re actually relatively abundant in the Earth’s crust, and the most common ones are found in concentrations similar to commonplace industrial metals such as tine, copper, and zinc. They’re called “rare earth” since they aren’t found in large, concentrated amounts. Rather, they’re mixed in with other elements, making them economically challenging to mine. As a result, only a few sources provide most of the world’s supply of rare earth elements.

By far, China is the world’s largest producer of rare earth metals, with a yearly production of 140,000 metric tons (MT). The US is the next largest producer, with an annual output of just 38,000 MT. The only US mine is the Mountain Pass mine in California. Even though the US is the second-largest producer, the US still heavily imports rare earth materials and metals since the output isn’t plentiful. In contrast to China, Vietnam and Brazil are the 9th and 10th largest producers with MT each.

Rare earth magnets are the strongest permanent magnets available and have significantly higher performance than ceramic/ferrite magnets (composed of strontium carbonate and iron oxide) and alnico magnets (composed of aluminum, nickel and cobalt).

How Rare Earth Magnets Are Separated

Since rare earth elements are found among other elements, they must be separated using a solvent extraction process. This process involves performing a chemical reaction to force one of the two elements to change phases (for example, going from a liquid to a solid). When this chemical reaction happens, the elements separate, and the concentrations of elements change. However, the change is minor, so it takes thousands and thousands of extractions to get to a purified phase. As a result, while the process works well, it’s a very inefficient and time-consuming process that produces a huge amount of waste.

Watch this video to learn more.

https://www.youtube.com/embed/ynhSd2Bskzc?autoplay=1&mute=1

Neodymium and Samarium Cobalt : The Two Most Common Types of Rare Earth Magnets

Neodymium (Nd-Fe-B) and Samarium Cobalt (SmCo) are the two most common types of rare earth magnet materials. Since they both come from the same series of metals, they have similar properties and crystal structures. Both types are extremely strong, and they tend to be brittle.

As described in the What Is a Rare Earth Magnet section, rare earth magnets are mined along with other elements, so they’re not pure elements. Neo magnets are composed primarily of neodymium, boron and iron, and samarium cobalt is composed of samarium and cobalt.

Both materials come in different grades, or strengths, and have different magnetic and physical properties. Check out our magnet comparison chart for product details.

These magnets tend to be brittle and are vulnerable to corrosion. Manufacturers typically nickel-plate the material to protect it from oxidation.

Choosing the Right Magnet for Your Application

From a business need to a home project, you could have a wide (or slim) range of requirements for a magnet. Don’t feel like you’re alone in your decision-making though - we’re always here to help you!

Here are some things to consider:

1. What type of application is it? Do you need a magnet to hold something in place? To organize an area? Or a specific application for a manufacturing floor?
2. How strong of a magnet do you need? You may need something that can do more (or less) than you think.
3. Will you have any special temperature requirements? Will the magnet be in the hot sun all day or in a refrigerated compartment?
4. What’s the space like? Is it tight? Large? Heavily trafficked?
5. What shape do you need? A block? Tube? Latch?

You may have other considerations as well, and we can help you with finishes, grades and pull ratings.

With so many magnet options, it can be a challenge to know which magnet is right for your project. Contact us, and we can help! Feel free to send us a picture, sketch or drawings of the drawings or the area, and any other information you have.

With over 20 million magnets for sale, we’ve got you covered! But don’t worry – that’s why we’re here. We truly enjoy helping customers find the right magnet. You can take several paths to find the right solution:

1. On our home page, you can search by who you are (a business or a consumer), magnet type, pull force, application and more.
2. Read our Choosing the Right Magnet page to ask yourself some questions about your magnet type.
3. Search our product catalogs to get ideas about your project and things you can do with magnets.

Customers rely on our team of magnet experts who guide product design, magnet material and technology, engineering, development, production and more.

Installing magnetic chucks in a production facility brings higher manufacturing capacity, speeds up processes, cuts down costs and increases profits — on condition that you pick the right type of magnetic chuck. Here’s a checklist to help you choose well.

With Walmag’s 30+ years of experience with magnetic chucks and lifting magnets, we feel confident enough to share our knowledge about various types of magnetic chucks. We’ve put together a helpful checklist for finding the most suitable magnetic chuck for any production facility. Go through it to make your preliminary choice, or at least have your answers ready — to questions any producer/seller of magnetic chucks will ask you.

Checklist for Choosing a Magnetic Chuck

1.   Machined Workpieces

Various properties of machined workpieces have to be considered when choosing a magnetic chuck:

Material

Magnetic force isn’t universal; some materials enhance it, some make it weaker. A workpiece needs to be made from a ferromagnetic material to be compatible with a magnet. The magnetic field becomes the strongest for low-carbon steel workpieces (with carbon contents within hundredths of a percent). High-carbon steel and alloy steel need to be clamped more forcefully as they contain multiple non-magnetic elements.

Thin Workpieces

Standard magnetic chucks securely clamp a 12 mm thin workpiece. Workpieces thinner than that require a magnet with denser poles to be clamped safely. Or you can use an additional top pole plate with the chuck — an imprint of the workpiece is milled in the pole plate, creating a form of sorts. When machined, the form holds the workpiece in place as the workpiece fits in the form snugly.

Recommended article:
Removable Trail Power Track Embedded Electrical Multi-Functional ...

If you are looking for more details, kindly visit YuYang Magnetic.

Using a strong magnetic chuck is not a solution for clamping thin workpieces as they let the magnetic field pass through them. The flux lines of the magnetic field close behind the workpiece, too far from it, which weakens the magnetic force. The workpiece will budge, move to the side, or even deform.

Surface of the Workpiece

The ideal workpiece for machining is flat, clean, and even. Dirt, dust, impurities, and additional layers (coats of paint or polish) always decrease a magnet’s holding force. Similarly, perforated workpieces and workpieces with openings will always be held less strongly by a magnet.

With these specific pieces, it’s best to calculate the magnetic force of a magnet individually. Or borrow a magnetic chuck to try it out. We do lend magnets in Walmag — we completely understand that some of our clients need to test the magnets before they take the plunge and buy them.

Shape of the Workpiece

For machining circular workpieces, we recommend getting a round magnetic chuck — a popular solution for machining saw blades, ring bearings, cylinders, and other round parts. A circular magnetic chuck allows you to perform multiple machining operations at once, without having to re-clamp the workpiece. Clamp your round workpiece just once and machine its inner and outer surfaces, as well as its front.

Even vs. Uneven Workpieces

To safely clamp a workpiece on a magnetic chuck, you need to clamp it evenly in multiple places. This is difficult to do with uneven workpieces — they need to be evened out before they’re clamped.

Our most popular Mastermill magnetic chuck deals with uneven workpieces by using firm and flexible pole extensions. Firm extensions are used to make a reference level, and flexible pole extensions are added to copy the shape of the workpiece. Once you turn the magnetic chuck on, flexible pole extensions fixate the workpiece on the reference level, making it perfectly even.

Neostar Round Magnetic Chuck

2.   Machining Operations

To pick the best magnetic chuck, make a list of all the machining operations you are going to perform on it. On our website, we divided our magnetic chucks into categories according to types of machining.

The most common machining operations are:

Milling

Need an all-purpose magnetic chuck for milling but also for other types of machining operations? Get the Neomill Compact magnetic chuck which can be used for planing, drilling, and withstands even heavy-duty grinding.

To clamp smaller and medium workpieces, get the Mastermill magnetic chuck. For larger workpieces, consider the Neopower chuck or Mastermill 70.

Drilling

The key here is prevention against drilling the workpiece through all the way to the magnetic chuck underneath and damaging the chuck. Use extensions which enable placing the workpiece higher on the magnetic chuck.

Grinding

Heavy-duty grinding requires a strong magnet with high magnetic force and a robust construction. For precision grinding, you need to prevent the magnet from warming up as heat is capable of deforming the workpiece. Electropermanent magnets are the perfect choice for precision grinding as they don’t get heated up (contrary to electromagnets) — such as our Grindmaster.

Lathe Turning

Round magnetic chucks are most popular for lathe turning operations as they guarantee free access to the workpiece from five sides without having to re-clamp the piece.

Precision Machining

Similarly to precision grinding, the key point here is to prevent the magnet from heating up. Electropermanent magnetic chucks are the best choice.

3.   Other Specifics of Your Production Facility

Consider all the factors at play in your production facility. Do you use a cooling agent during machining operations? A waterproof magnet might be a good idea — ideally made of monoblock. A monoblock magnet lacks creases through which liquid could get in the core of the magnet. The same logic applies to facilities with a high concentration of dust.

4.   Control Unit

In the case of some magnetic chucks, their control unit can be integrated into the control unit of the machining device, allowing the operator control clamping and machining on one display.

When getting a large system of magnetic chucks, decide whether the control unit should control the entire magnetic set or you need to control individual magnets in the set. The latter is a common requirement for large machines which enable the operators to perform machining operations on one side, while still getting workpieces ready for machining on the other side.

We’ll happily design and manufacture a magnetic clamping system for you. In such cases, we prepare a blueprint for the magnetic set, based on your machine’s precise measurements. On the blueprint, we mark placements of magnets for various machining operations.

A High-Quality Magnetic Chuck Lasts for Years

A high-quality magnet lasts for years! Our 30+ years of existence give us enough credit to  vouch for our magnets’ longevity. On top of that, we provide service and refurbishment for all our magnets.

Want more information on Magnetic Components Factory? Feel free to contact us.