Neodymium Discs

 
Neodymium (rare earth) NdFeB disc magnets

Neodymium magnets or NdFeB disc magnets are round coin-shaped NdFeB magnets of varying diameter and thickness. Generally the Neodymium disc magnets are axially magnetized i.e. one circular flat face is a North pole, the other circular flat face is a South pole with the distance between the flat faces (the disc thickness) being the distance between the poles (the magnet is magnetized along the central axis of the Neodymium disc magnet). All our NdFeB disc magnets are supplied as axially magnetized NdFeB magnets unless otherwise stated.

Diametrically Magnetized Neodymium Disc Magnets

Diametrically magnetized Neodymium magnets are possible (i.e. the magnet is magnetized across the diameter perpendicular to the central axis - like being magnetized from 12 noon through to 6pm when looking down onto the magnet circular face). If you were to put a row of cans flat face down onto a table to form a single line of touching cans, this is how diametrically magnetized magnets would normally attract each other - point contact. We produce the majority of these as custom magnets.

The axially magnetized Neodymium disc magnets can be stacked in attraction to create thicker magnets (in multiples of the magnet thickness). Increasing the NdFeB disc magnet thickness can give an increase in magnetic output from the magnet but there is a thickness at which adding extra magnet height gives less and less performance benefit (the performance plateaus off) - if more performance is needed then a bigger diameter magnet should be considered (or ask us for advice). So if you are not sure how thick your magnet should be then consider getting a thinner magnet and building up height by stacking until you empirically gain the performance you require.

The Neodymium disc magnets can be fixed in place by using adhesives (e.g. superglue / cyanoacrylate, two part epoxies, etc). Holes can also be machined into parts for the magnets to be glued in place or inserted deeper and potted away to hide the magnet or give it extra corrosion protection. Sometimes the discs are covered to hide them e.g. in furniture making a thin wood layer is put over the magnet to hide it and improve the aesthetic appearance of higher value wooden furniture (bearing in mind that it introduces an air gap which will lower the magnetic pull force which can be gained by using thicker NdFeB magnets and/or bigger diameter NdFeB magnets).

The Neodymium disc magnets give more pull force when attracting another magnet than when attracting a ferromagnetic (e.g. mild steel) part