Smallest Inner Diameter for Multi-Pole Bonded Ferrite Rings - What’s Realistic

So what’s realistically possible?

For inner diameter, we’ve seen production runs down to around 4–5 mm with multi-pole anisotropic bonded ferrite. Can it go smaller? Possibly, but the molding and orientation process gets trickier, and yield may drop. That’s something to test case by case.

What about pole count? Yes, 24 poles or more is possible, especially if the ring diameter gives enough room for individual pole arcs. But here’s the thing: the higher the pole count, the more attention needed on orientation fixture precision. It’s not a simple “yes” for every geometry.
And tolerance? ±0.05 mm is a common request. In many cases we can hold that, but it depends on part size and feature complexity. We usually start with a feasibility review on the drawing.
As a permanent magnet manufacturer, we avoid making absolute claims about performance capabilities. Instead, we rigorously test our materials and processes to reliably meet your specific application requirements.If you‘re designing a micro fan or pump rotor and need a honest conversation about what bonded ferrite multi-pole rings can (and can‘t) do, just reach out to us: info@tecomag.net.