Neodymium Ring Magnets

Product Information

Neodymium rings are one of the most popular shapes of rare earth magnets.  Magnetic rings are often used in joinery and shop-fitting as they may be recessed and screwed into position. Although not as strong as Neodymium Discs, the hole in center of the ring magnet ensures great versatility. The higher permeance coefficient makes neodymium ring magnets ideal for many applications. This type of permanent magnet can be used in science projects or experiments, medical applications, cabinetry, water conditioning, loudspeakers and other commercial and industrial purposes.

Neodymium Ring Specification

Dimensions

Neodymium Rings can be customized in width, thickness, and ring diameter. Neodymium rings may have a custom shape hole and may be open or closed.

Our strong ring neodymium magnets N35, N38, N40, N42, N45, N50 and N52 ,N35H etc are in many sizes. When we call ring magnet, tube magnet, or maybe permanent magnets rare earth strong ring neodymium magnets, they are very similar, just the height or length are different.

Per your request or drawing

We can customized as required

The magnetized direction is always through axial, but some customers use it to assemble their sensor, then the magnetized direction is through the dialectally.

Properties（Theoretical）

The most appropriate temperature for Neodymium Magnets

The performance of a neodymium magnet is affected by temperature. As the temperature gets colder, neodymium magnets get stronger, and they even operate better at lower temperatures. Neodymium magnets are said to be able to function well in temperatures as low as -130 ° C.  It is also possible for certain grades of neodymium magnets to be exposed to very high temperatures before they begin to change their properties and, either temporarily or permanently, lose their magnetism. 

Neodymium Magnets decrease in magnetic strength by 0.11% for every degree celsius of temperature increase. If the maximum operating temperature is not exceeded, this small loss can be fully recovered on cooling. In the case of exceeding it, the small loss will not be recovered on cooling. The magnetic field output of Neodymium magnets increases with temperature up to 80° C and after that point, they begin to lose their effectiveness. There are different levels of Neodymium 35 temperature rating (M, H, SH, UH, EH, or AH). Higher temperature versions (NxxM, NxxH, NxxSH, NxxUH, NxxEH, NxxVH/AH) are rated from up to +100⁰ C to a maximum of up to +230 ⁰ C.  The magnetic performance will continue to decline after successive hot-cold cycles. Without careful design of the magnetic circuit, you should not use these magnets in temperatures above 130° C (240° F).

The permanent demagnetisation fields and radiation can also affect neodymium magnets, so the magnet must always be fully understood according to the environment in which it will be used.

Neodymium Magnets require surface treatments

In humid conditions, magnets without a surface coating (such as plating) may rust. Therefore, all  Neodymium Magnets or Rare Earth magnets should have some form of protective coating to minimise and ideally prevent corrosion. Uncoated is not advised. The default / standard protective coating is Ni−Cu−Ni plating. Other coatings/finishes exist (over 40 finishes are currently available). Where maximum corrosion resistance is required for NdFeB, consider using the increased corrosion resistance range of NdFeB alloys.

Advantages & Disadvantages of Neodymium Magnets (NdFeB)

Advantages 

· Maximum performance relative to size. Ideal for restricted space or compact applications. 

· Can be used in extremely cold conditions (e.g. in liquid nitrogen).

· Standard Neodymium NdFeB Magnet is rated to +80 degrees C (176F) maximum. Can be rated to +100 (212F), +120 (248F), +150 (302F), +180 (356F), +200 (392F) and +220/230 degrees C (428/446F) with higher Hci versions.

· High coercivity (Hci) to resist demagnetisation.

· NxxT and L-NxxT alloys have better corrosion resistance than standard NdFeB but still needs coating.

Disadvantages

· Requires a protective coating to prevent the iron in the alloy from corroding (rusting).

· NxxT and L-NxxT alloys are much more expensive and will still show signs of corrosion.

· Higher temperature versions contain more Dy element increasing their cost.

· Nd and Dy prices affect the production cost.

Above 150-180 deg C (302-356F), SmCo may be better

Features include:

• Neodymium magnets are the most powerful commerically produced magnets.

• Neodymium magnets are hard and brittle and may chip or break if dropped.

• Disc Neodymium magnets are magnetized through the thickness or diametrically magnetized.
• Uncoated neodymium magnets may corrode in humid conditions
• Operating temperatures vary among material grades.Usually ranges from 80°C to 220°C. For a comparison of neodymium material grades, please visit our chart of material properties.
• Keep cautious when handling magnetized neodymium magnets, their exceptional magnetic force may cause them to attract to metal (or to each other) so strongly that fingers in their path could prove painful.

Typical Applications for Rare Earth Neodymium Magnets

Neodymium magnets are available in several different sizes and variations, including neodymium bar magnets or neodymium blocks, neodymium disc magnets, neodymium pot magnets, neodymium ring magnets. They are also available with attachments such as hooks or threaded  attachments. They are also available with rubber coatings or adhesive backings. This gives a vast choice to suit a variety of applications including:

· Neodymium Magnets for Motor and Generator drives including, wind and tidal turbines 

· Meters

· Neodymium Magnet Speaker, Audio Equipment - headphones, microphones

· Computer Disc Drives and Printers

· Automotive (clamps, sensors, alternators, interior trims)

· Precision Magnets for Aerospace - sensors, navigation equipment

· Fine particle Magnetic Separation (magnetic rods, magnetic grids, etc) – 10-12kG (22-26lbs) systems

· High-performance magnetic clamps and pot magnets

· Electronics  - switches, relays, sensors

· Lifting Heavy Ferrous materials - see neodymium magnetic lifters    

Applications of Neodymium Ring Magnets

Rare Earth Ring Magnets are often used in joinery and shop-fitting as they may be recessed and screwed into position. Although not as strong as Neodymium discs, the hole in centre of the ring magnet ensures great versatility.

This type of permanent magnet can be used in science projects or experiments, medical applications, cabinetry, water conditioning, loudspeakers and other commercial and industrial purposes. The higher permeance coefficient makes Neodymium ring magnets ideal for many applications.

Neodymium rings are one of the most popular shapes of rare earth magnets. We supply a wide range of ring magnets in different sizes and with several different coatings such as Nickel, Zinc, Epoxy or Gold to prevent and reduce wear and corrosion.

Packing of Neodymium Ring Magnets

Standard Packing:

Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 440 gallon liquid totes Special package is available on request.

ATTs’ Neodymium Ring is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition.

Chemical Identifiers