Air Gap – The air gap is the non-magnetic distance between two magnetic poles measured externally.

Anisotropic – A material with properties that vary depending on direction. Neodymium magnets are the most common example of anisotropic magnets.

B/H Curve – A graph that plots magnetic field strength (H) against magnetic flux density (B). This curve helps determine the properties of a magnetic material.

Maximum Energy Product (BHmax) – The point on the B/H curve where the magnet produces maximum energy. It is typically measured in MegaGauss-Oersteds (MGOe).

Brmax (Residual Induction) – Also called residual flux density. It is the magnetic induction remaining in a saturated magnet once the external magnetizing force is removed. This occurs when the hysteresis loop intersects the B-axis at zero magnetizing force and is usually seen with no air gap.

C.G.S. – An abbreviation for the centimeter-gram-second system of measurement.

Coercive Force (Hc) – The strength of the demagnetizing force required to reduce a magnet’s induction to zero after saturation. Measured in Oersteds.

Curie Temperature (Tmax) – The temperature at which a magnet completely loses its magnetic properties.

Demagnetization Force – A magnetic force applied in the opposite direction of the original magnetizing force. Common demagnetizing influences include heat and mechanical vibrations.

Demagnetization Curve – Part of the hysteresis loop that illustrates how a magnet performs under actual operating conditions. It is also referred to as the B-H curve.

Dimensions – The physical measurements of a magnet, including any coatings or platings.

Dimensional Tolerance – The allowable variation in the magnet’s finished dimensions from its specified nominal size.

Dipole Moment (M) – A measure of the strength and orientation of a magnet’s external magnetic field.

Electromagnet – A type of magnet that consists of a solenoid wound around an iron core. It only exhibits magnetic properties when electric current flows through the coil.

Ferromagnetic Material – Materials such as iron, nickel, and cobalt that can conduct or concentrate magnetic flux and are used to create magnets.

Gauss – The unit of magnetic flux density (B) in the CGS system.

Gauss Meter – A device used to measure the instantaneous value of magnetic induction (B), also known as a DC magnetometer.

Gilbert – In the CGS system, Gilbert is the unit of magnetomotive force (F).

Hysteresis Loop – A plot of the B/H curve showing how a magnetic material behaves when it is magnetized, demagnetized, and then re-magnetized in the opposite direction. The loop’s shape and size indicate whether the material is magnetically “hard” or “soft.”