What Does Pull Force Mean?
Pull force, also known as magnetic pull, is a measure of the strength of a magnet’s magnetic field. It is the force that a magnet can exert on an object made of ferromagnetic material, such as iron, nickel, or cobalt. The pull force of a magnet is determined by the strength of its magnetic field and the size and shape of the magnet.
Often measured in pounds or kilograms, the pull force is the force required to pull that magnet straight free from a thick steel plate. The pull force also tells you the limit of that magnet’s holding power.
Pot magnets are widely used for holding applications. Generally, any pot magnet with a pull force above seven pounds (3 kg) can pinch your fingers. Stronger magnets can be even more dangerous and should only be handled by experienced individuals. We always recommend hand and eye protection for large magnets.
Magnets stick best to ferromagnetic surfaces and do not stick to chrome, brass, aluminum, silver, gold, wood, plastic, or tile. Attaching magnets to these surfaces is best accomplished with countersunk or self-adhesive pot magnets.
What Affects Pull Force?
While the pull force rating enables you to determine how much weight or tension a magnet will hold, there are several other factors to consider which can affect a pot magnet’s pull force.
Vertical vs Horizontal Placement
The placement of the magnet is an important part of the equation. A pot magnet placed vertically, such as on the underside of a steel beam or table, will hold its listed pull force weight. A pot magnet mounted laterally/horizontally, such as on the side of a refrigerator or file cabinet, will only hold 30 percent or less of its listed pull force due to gravity and the potential for the magnet to slide down the attachment surface.
The pot magnet air gap is the distance between a magnet and the ferromagnetic material that it is attracting or repelling. The air gap is an important factor to consider because it can dramatically affect the strength of the magnetic field and the performance of the magnet.
Pot magnets lose holding power exponentially as you add distance between them and the other magnet or ferromagnetic material. Even seemingly small air gaps caused by debris or paint will impact the performance of the pot magnet. This is because the magnetic field lines become more spread out over a larger distance, resulting in a weaker overall field. This is a factor to consider if you are encasing the pot magnet in fabric or behind a piece of wood.
The composition, size, and thickness of the steel can also affect the performance of a pot magnet. Different types of steel have different magnetic properties, and some types of steel are more magnetic than others. For example, low-carbon steel is generally more magnetic than high-carbon steel, and stainless steel is generally less magnetic than other types of steel.
Choosing the Right Pot Magnet
It can be challenging to select the best pot magnet for your specific application due to the numerous factors that can impact a magnet’s pull strength. Testing the pot magnet in your application is the best approach to learn whether it will perform as needed. You may always get in touch with our pot magnet experts if you have any questions or want assistance selecting the right pot magnet. We will be delighted to assist you in making the best pot magnet choice for your needs.