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Gauss and Neodymium Magnets

What Is Gauss?

Gauss is a unit of measurement that describes magnetic induction, aka magnetic flux density. The term is a relatively common term among industrial neodymium magnet professionals, and it has its origins in Carl Friedrich Gauss—the German mathematician and physicist. They first measured magnetism using mathematical principles.

A neodymium magnet’s gauss is different from its pull strength, so the gauss test using a gauss meter is not a strength test. Testing the power of a neodymium magnet requires attaching a steel plate to it while an operator pulls on the steel plate until it comes off. On the other hand, the gauss test seeks to determine a neodymium magnet’s peak gauss.

We said the gauss is the unit of measurement that describes magnetic induction or magnetic flux density. It means that the gauss represents the intensity of the magnetic field in a given location.

It may also refer to the residual flux density, i.e., the magnetic induction in a saturated magnetic material after the magnetizing field has been removed, or the distance and direction of the magnetic field generated by a neodymium magnet. A gauss test can help determine the strength of a magnetic field but not the pull or holding force of that neodymium magnet. And a higher gauss does not necessarily mean a stronger pull force.

For instance, a neodymium magnet with a high pull strength is required in virtually every holding application. But a high gauss or magnetic induction is necessary for specific applications, like in a sensor or health equipment.

While the size of a neodymium magnet may not affect its gauss rating, meaning two neodymium magnets of different sizes may have the same gauss rating, the larger neodymium magnet will have a stronger holding force than the smaller one. Attaching two identical neodymium magnets of the same gauss rating will increase their magnetic field and pull strength, but their gauss will remain the same.

What’s the Difference Between Gauss and Tesla?

Tesla is another unit of measurement that is very similar to gauss. They moth measure magnetic induction. The difference is that both units belong to two different systems of units.

Gauss belongs to the CGS (centimeter-gram-second) system of measurement that recognizes the centimeter as a measure of length, the gram as a measure of weight, and the second as a measure of time.

On the other hand, Tesla belongs to the international system of units, aka SI. The SI is the modern form of the metric system and is maintained by The General Conference on Weights and Measures (GCWM).

Despite belonging to different systems of units, gauss and Tesla represent magnetic induction. Another difference is that Tesla has a higher value than gauss, but they are easily converted by 1 tesla = 10,000 gauss.

Overview of Neodymium Magnets

Neodymium magnets, also known as NdFeB, NIB, or Neo magnets, are the most popular and widely used rare earth magnets. They are classified as permanent magnets because of their ability to retain magnetism permanently after their initial magnetization, provided they are not exposed to any demagnetization forces.

They are manufactured from an alloy of neodymium, iron, and boron; depending on the manufacturing process, they could either be sintered or bonded. Because of neodymium magnets’ strength and durability, they have replaced other permanent magnets such as alnico and ceramic.

There are different grades of neodymium magnets with unique specifications. Below is a quick overview of our neodymium magnets and their specs.

Grade Max Operating Temperature Curie Temperature
N 80°C or 176°F 310°C or 590°F
M 100°C or 212°F 340°C or 644°F
H 120°C or 248°F 340°C or 644°F
SH 150°C or 302°F 340°C or 644°F
UH 180°C or 356°F 350°C or 662°F
EH 200°C or 3922°F 350°C or 662°F

Gauss Rating of Neodymium Magnets.

Neodymium magnets are the strongest types of magnet available, and they can have gauss ratings of over 13,000 and an insane amount of sheer strength. Below is a comparison of neodymium magnets gauss against other available magnetic fields.

  • 14,600 Gauss– Neodymium (NdFeB) magnet (grade N50)
  • 12,500 Gauss– Alnico (AlNiCo) magnet (grade 5)
  • 11,000 Gauss– Samarium Cobalt (SmCo) magnet (grade 2:17)
  • 3,700 Gauss– Ferrite magnet
  • 100 Gauss– Standard refrigerator magnet
  • 5 Gauss– Earth’s magnetic field at its surface

Below are the residual flux density ratings for our grade N neodymium magnets in gauss and tesla:

Grade KiloGauss (kGs) Tesla (T)
N30 10.8 – 11.2 1.08 – 1.12
N33 11.4 – 11.7 1.14 – 1.17
N35 11.7 – 12.1 1.17 – 1.21
N38 12.2 – 11.6 1.22 – 1.16
N40 12.6 – 12.9 1.26 – 1.29
N43 13 – 13.3 1.3 – 1.33
N45 13.3 – 13.7 1.33 – 1.37
N48 13.7 – 14 1.37 – 1.4
N50 14 – 14.6 1.4 – 1.46

For a complete list of available grades and their ratings, please visit our specifications/grades page

What Is the Highest Gauss Rating Ever?

Although neodymium magnets are the strongest rare-earth permanent magnets available and could have gauss ratings of over 14,000, as shown above, there are neodymium magnets (usually neodymium) that have even greater gauss ratings.

Neodymium magnets used in health applications, particularly in scanning equipment like MRI machines, usually have a rating of between 20,000 and 70,000 gauss or 2 to 7 tesla. Some neodymium magnets have up to 450,000 gauss rating, but you can only find them in research labs where scientists use them for special purposes.

Difference Between Surface Gauss, Pull Strength, and Remanence.

Discussing neodymium magnets can sometimes be tedious because several terms refer to different values, all of which contribute to their performance and efficiency. Three of those terms are surface gauss, pull strength, and remanence.

Surface gauss

The surface gauss refers to the strength or density of a neodymium magnet right at its surface. If you can get a magnetometer up to its skin, the rating you will get here is the surface gauss, and it can be a good indicator of how well the neodymium magnet will perform in its application.

The surface gauss is usually lesser than the gauss at its core, so it’s essential to measure the surface gauss of the neodymium magnet to ensure its compatibility with the intended application.

Pull strength

The pull strength, as described above, refers to the force required to separate a neodymium magnet from a steel plate. This value depends mainly on the neodymium magnet’s maximum energy product or BHmax, i.e., the sheer strength of the magnetic force the neodymium magnet generates.

A neodymium magnet’s pull force also depends on the neodymium magnet’s shape and size. That is, a larger neodymium magnet will have the capacity to attract objects at a farther distance than a smaller neodymium magnet and will also have a higher pull strength regardless of whether they are of the same rating.

Certain factors may affect the actual pull force of a neodymium magnet during application. They include the surface of attachment, the permeability of the material, placement of the neodymium magnet, and air gap, which refers to any non-magnetic material between the neodymium magnet and the ferromagnetic material, e.g., coating, paint, foam, wood, paper, and others.

Remanence

Remanence, derived from the word “remain,” refers to the amount of magnetic field left in a saturated magnetic material after exposure to an external magnetizing field. It is also the residual magnetic induction or residual flux density.

Among neodymium magnets’ qualities are their high remanence and coercivity, i.e., the ability to retain magnetism permanently and high resistance against demagnetization forces. A neodymium magnet’s remanence also determines the strength of its magnetic field because the magnetic field gets weaker as it covers a larger area.

How to Measure Neodymium Magnets’ Field Strength.

You can measure the gauss or field strength of a neodymium magnet using a gauss or tesla meter. It is an exercise you can perform by yourself with these steps:

  1. Gather your equipment: the neodymium magnet to be measured, the gaussmeter, and a fixture. If you need to measure multiple neodymium magnets, you’ll need the fixture to hold the probe on your gaussmeter.
  2. Place the neodymium magnet on a flat surface,
  3. Measure their balance by bringing the tip of the probe coles to the surface of the neodymium magnet.

Since the sensor of the gauss meter is at the tip of the probe, hold it in place with a fixture to get repeatable measurements on one or more neodymium magnets.

Wait a moment for the gaussmeter to read out the highest value. That’s your neodymium magnet’s gauss rating.

Where to Get High-Quality Neodymium Magnets in Bulk

Whether you need a neodymium magnet with a high gauss rating or one with an exceptional pull strength, you can count on ROBO Magnetic to help you design, manufacture, and supply neodymium magnets that you require for your application. For the past sixteen years, we have provided a wide range of neodymium magnets, from the N30 to the N52.

Our professionals are experts in the field of magnetism, applying the best practices and using state-of-the-art technology to improve the manufacturing process of our neodymium magnets. ROBO Magnetic is one of China’s biggest neodymium magnet manufacturers and suppliers, shipping an estimated 800 tons of neodymium magnets yearly. Whether you need standard or custom-shaped neodymium magnets, we can help you. Contact us today for the best customer service.

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Article by

ROBO Magnetic Product Team

We are the manufacturer with 16 years of experience in custom neodymium magnets.

Need A Quote? Get in touch with us directly.

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