A magnet is a material or object that produces an invisible magnetic field, which is the property that causes the magnet to attract to or repel from other magnets. These invisible lines of magnetic field are referred to as “lines of flux”.
A Permanent Magnet is a magnet that remains magnetized at all times without the assistance of an outside influence of energy. A soft magnet is one that does not stay magnetized unless there is a magnetic field or current.
Pull force calculations of magnet are based upon the size and shape of the magnet against a piece of steel. The pull force is a calculation of the amount of force it takes to release the magnet from the piece of steel.
Sheer force is a calculation of the force required to move a magnet parallel to a ferrous surface in order to break the bond between the magnet and the ferrous surface.
Magnets are produced in different materials. The most popular magnets are neodymium, samarium cobalt and ferrites.
Neodymium magnets are the strongest magnets. They can produce a large amount of magnetic field in a small package. These magnets are used in almost every industry, and are especially vital in consumer electronics, automotive, motors, fluid handling, and speakers.
Selection of the correct magnetic material is extremely vital. To understand the issues involved with selecting a magnet, view our FAQ’s.
Selecting the appropriate coating is just as important in most cases as is selecting the correct magnet. Magnets can be coated in a wide variety of materials, each with a distinct purpose.
The coatings on a magnet are non-magnetic and will not affect the performance of the magnet. Consideration of the thickness of the coating should be taken into account when designing air gaps and holding assemblies.
All magnets have a north and south pole. When like poles are pushed together they will repel, when opposite poles are pushed together they will attract.
When Anisotropic magnets are manufactured, they will have a defined direction of magnetic field. This magnetic direction cannot be changed.
When Isotropic magnets are manufactured, they will have no defined direction of magnetic field, and will can be magnetized in any direction.
When a magnet is manufactured, it is not magnetized until the final process. Magnets can be purchased magnetized or unmagnetized, but can only be magnetized using a strong magnetic field.
Magnet shapes can be almost anything imaginable. Advancement in manufacturing techniques has allowed for the production of magnets in very easy shapes (disc, square, rectangle), or extremely complex shapes.
A neodymium magnet can be demagnetized using heat, or an opposing magnetic field. However, if magnet selection is correct during the design phase, the correct magnet can be selected to avoid demagnetization.