Neodymium Ring Magnets

Overview - Neodymium Ring Magnets

Neodymium (rare earth) NdFeB ring magnets / NdFeB countersunk ring magnets / NdFeB counterbore ring magnets

A  ring magnet or NdFeB ring magnet is a NdFeB disc magnet with a concentric hole inside it. A Neodymium countersunk magnet is a Neodymium ring magnet with one side appearing as a standard ring but the other side has an angled countersink to take a screw head, the angle usually being (but not always) 90 degrees. It is a ring magnet with a cylindrical flat-bottomed hole on one side that enlarges the main central hole to take a cap head screw.

Alternative Names for Neodymium Ring Magnets

Neodymium ring magnets are also known as Neodymium pure ring magnets or Neodymium countersunk magnets, and Neodymium counterbore ring magnets. These  variations are nearly always axially magnetized - the magnet is magnetized along its central axis. So one flat end face is a North pole and the other flat end face is a South pole.

For pure rings, turning over the ring changes the polarity. But for the NdFeB countersunk rings and the NdFeB counterbore rings the countersunk or counterbore side will be a North or a South and the other end (which will visually look like a pure ring) will have the opposite polarity). In some applications where a NdFeB counterbore ring is attracting another NdFeB counterbore ring or a NdFeB countersunk ring is attracting another NdFeB countersunk ring you will probably require a set of Norths and a set of Souths to achieve unlike poles attracting.

If the magnets are attracting onto a ferromagnetic surface only, the any type of ring magnet (regardless of axial polarity direction) will be fine to consider using (combinations of Norths and Souths together will be fine - sometimes a N-S-N-S alternating pattern may give a small boost in performance if the magnets are close enough). When we state a ring magnet is a North, the countersunk face or counterbore face will be the North pole face (the other end will be the South pole face). When we state a ring magnet is a South, the countersunk face or counterbore face will be the South pole face (the other end will be the North pole face).