A Basic Guide to Magnetic Strength
If you’re responsible for procuring magnets for your business, you should have a basic understanding of the variables that impact a magnet’s strength. Why? Because strength relates back to safety, reliability, efficiency, and cost-effectiveness. To help you meet your responsibilities and choose the best possible product for your application, we put together this quick and easy guide to magnet strength.
Part One: Gather Information
First, let’s talk about magnetic field and force. The field is a region around the magnet – a moving electric charge – within which the magnetic force acts upon something else. To put it more simply, the magnetic field is the “cause” and the magnetic force is the “effect,” or consequence of the field. Two objects with a charge moving in the same direction exhibit a force of attraction (opposite poles). Objects with a charge moving in opposite directions exhibit a repulsive force (similar poles).
Force and field can both be impacted, which is why you should always begin your product search with a series of questions such as:
- What temperature will the magnet be stored/used at?
- Will it be used in a horizontal or vertical application?
- What shape best suits the application?
- Do you require some type of coating?
- What size magnet do you need?
If you don’t know the answer to these questions, feel free to call us at (1-304) 257-1193.
Part Two: Measure Strength
One might choose to view magnetic strength through the lens of pull force or magnetic field. The pull force is essentially the force needed to pull two magnets apart, or to remove a magnet from some other surface, like steel. While the magnetic field is the measurement of strength and direction at a specific point. This would be expressed in Gauss or Tesla (note that 1 Tesla equals 10,000 Gauss).
Three common modes of strength measurement include Gaussmeters, Magnetometers, and Pull-Testers. Gaussmeters measure in Gauss, Magnetometers measure in Gauss or arbitrary units, and Pull-Testers measure in pounds, kilograms, or a preferred unit of force.
Pull force is dependent on several variables, including the temperature and size of the magnet (like magnetic force and field), and also surface condition and pull angle. While altering size is one way to impact a magnet’s strength, it can become expensive to shop for larger magnets. Other variables of note include material and shape.
Part Three: Material and Shape
We recently updated our website to include a search panel where you can select the desired size, pull force, shape, and magnetic material. Apex offers three out of the four classes of permanent magnet material, in order of strongest to weakest: neodymium, samarium-cobalt, and ceramic-ferrite.
To a lesser degree, shape will also affect strength, which is why Apex also created a grid of popular sizes. To find your desired size, first, select the desired shape for your application (cylinder/disc or block/bar/cube). Then, choose your mode of measurement (decimal inches or millimeters). Finally, decide how you want the results displayed. Would you prefer to see the results organized by part number or stock keeping unit (SKU) or by estimated pull force? With Apex’s newest search panel and popular size grid, you’ll find your next magnet in no time.