How is the Strength of Rare Earth Magnets Measured?

Rare earth magnets are known for being the most powerful types of magnets available—but how is this strength measured? There are many different ways to measure a magnet’s strength, but when people ask “how strong is this magnet?” they are typically referring to a magnet’s holding strength. Below, we will explain the different properties that determine a magnet’s strength, as well as how to measure a magnet’s holding strength.

Unique Magnetic Properties of Rare Earth Magnets

When measuring the strength of a magnet and comparing it to another magnet, its magnetic properties must be taken into account. A list of some of the most important magnetic properties are:

Remanence (B)—a measurement of the magnetic field’s strength.

Coercivity (H_ci )—a magnetic material’s resistance to demagnetization.

(Maximum) Energy product (BH_max)—a permanent magnet’s magnetic energy, which is the maximum value of magnetic flux density (B) times magnetic field strength (H).

Rare earth magnets have high remanence and high coercivity, meaning they have magnetic fields with a high strength that are also very resistant to demagnetization. Additionally, they have a high energy product. It is the combination of these three factors that contribute to the immense power of rare earth magnets.

Measuring Magnetic Strength

When a magnet’s strength is measured, the specific value being measured tends to be the magnet’s field strength, which is the ability of an electric current to induce a magnetic field at a given point. A magnet’s field strength is the measurement of how magnetic force is distributed around a magnet. This measurement tends to be referred to as holding force, or a magnet’s “pull strength.” A magnet’s pull strength refers to how much force is required to pull a magnet away from a flat steel surface it is in full contact with. This unit can be measured using a pull test.

When you are selecting a rare earth magnet, you will see a measurement labeled “pull force,” which refers to the maximum weight that a rare earth magnet is able to hold. As an example, if a rare earth magnet has a pull force of 60lbs, it means the magnet can safely hold an object that weighs 60 lbs.

Measuring Rare Earth Magnets with BuyMagnets.com

BuyMagnets.com offers pull test kits that allow you to measure the strength of rare earth magnets you already own, allowing you to assess their performance over time and make sure they are suitable for applications you intend to use them in. Additionally, we have multiple magnetic calculators on our website to help you select the best magnet for your application.

To learn more about magnetic properties and how magnetic strength is measured, contact our experts today.