Magnetizer & Fixture

Selection criteria

Stored energy, peak current, fixture pole count and cooling.

Supply chain

Dongguan, Foshan and Shenzhen motor-automation builders make magnetizers, often combined with surface-field inspection and magnet insertion; German and Italian specialists still lead at the high end. The multi-pole fixture is the hard part — buy magnetizer and fixture as a package and verify the field pattern on your own rotor.

Buyer FAQ

Magnetize before or after assembly?

Post-assembly magnetizing (magnets already bonded in the rotor) avoids handling strong magnets, keeps chips off the rotor and gives an exact pole pattern; it needs a multi-pole fixture designed for your rotor. Pre-magnetized segments are used when the fixture would be too costly or the magnet grade is too hard to saturate in place.

How strong a field is needed?

Sintered NdFeB needs roughly 2.5–3 T (≈ 2,000–2,400 kA/m) to saturate, high-coercivity grades more; ferrite needs about 1–1.5 T. The capacitor-discharge energy, peak current and fixture design together decide whether the magnet saturates.

How do I verify the result?

Scan the surface flux around the rotor with a Hall probe: peak per pole, pole-to-pole spread (often ≤ 5 %) and pole position. Back-EMF on the finished motor is the final check.

Where it is used