Measuring Pull Strength
How Strong Is My Magnet?
It’s common for magnetic assemblies to have a rating of pounds pull (or Max Force) in order to provide users with guidance into the product’s capability.
Magnetic pull strength is a reliable method of measuring the maximum strength, or holding power, that a magnetic assembly has before it is separated from a steel plate.
It is measured in pounds and obviously, the higher the pull strength, the greater the strength of the magnetic assembly.
The Testing Process
The entire magnetic surface of our magnetic assemblies is tested against a .5 inch thick, ground steel plate. Beginning with a clean magnetic surface and a clean steel surface, the magnetic assembly is attached to the center of the steel plate. A hook with a measuring device (dynamometer) is attached to the assembly. It slowly pulls the magnet upward until sufficient force (breakaway force) to break the assembly from the plate has been created. The measuring device records the pounds pull.
By repeating this test multiple times, we can establish an accurate reading and pounds pull rating (or Max Force) for the magnetic assembly.
It is important to note that pull strength will vary with:
- Differing thicknesses of steel (particularly less than .5 inch)
- Types of steel composition
- Coatings on the steel, including paint or grease
- Uneven surface area, such as rust
Choosing a magnetic assembly might be as straightforward as selecting the right pounds pull for your application. Considering things like how many poles are needed; if there will be air gaps at any point on contact; how hot or wet the environment is; and the storage area can lead to the best decision for the type of magnet for a project.
Due to the many variables that can affect magnet strength, we always recommend testing the magnet in your particular application first. We also recommend consulting with one of our magnet experts to help select the correct magnet for your application.