Ferrite ring magnets / Ferrite Countersunk magnets
A ferrite ring magnet is a ferrite disc magnet with a concentric hole inside it. A ferrite countersunk magnet is a ferrite ring magnet with one side appearing as a standard ring but the other side is seen as an angled countersink which allow a screw head to fit inside,the angle usually being (but not always) 90 degrees. A ferrite counter bore ring magnet 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 inside the magnet.
Ferrite ring magnets are also known as ferrite pure rings, ferrite countersunk magnets, and ferrite counter bore magnets. All the ferrite ring magnets are nearly always axially magnetised -the ferrite magnet is magnetised along its central axis. Unless stated otherwise the ferrite ring magnets, ferrite countersunk ring magnets and ferrite counter bore ring magnets are all axially magnetised.
Axially magnetised magnets have one flat end circular face as a North and the other flat circular end face as a South.For pure ferrite rings, polarity is changed by simply turning the magnet over.For the countersunk and counter bore ferrite ring magnets, North versions have a North at the countersunk / counter bore side (with a South at the other end -which appears like a normal ring); South versions have a South at the countersunk / counter bore side (with a North at the other end - which appears like a normal ring).
In applications where the ferrite ring magnets are clamping onto ferromagnetic surfaces (e.g. mild steel), any version could be used - sometime placing in a N-S-N-S arrangement may give a small increase in performance as the magnets link their magnetism in a positive way.
In applications where magnets are attracting magnets, just ensure that a North face of one magnet is attracting a South face of another magnet (unlike poles attract; like poles repel).
When screwing ring magnets in place please do not over tighten the screws otherwise it may cause the Ferrite ring magnet to break. Ferrite magnets are brittle (like all magnets) and are not designed for load bearing (e.g. high clamping forces)
We produce custom magnets. If you want ferrite ring magnets produced to a different grade, this is possible. We can also produce different shapes, including double countersink and double counter bore. Diametrically magnetised ferrite rings are also possible. Some ferrite magnets may have a tooling charge.
If you are in any doubt about the choice of ferrite ring magnet, its size or need technical assistance, please contact us.And if you need a quotation for higher quantities or a custom ferrite ring magnet shape, please contact us
For the maximum magnetic strength see our range of Neodymium (rare earth) magnets.