Will the magnets in a brushless motor fall off at 800 rpm?

During the use and maintenance of brushless motors, the question of whether magnets will fall off has always been a key concern for users and engineers. I recently saw an online inquiry asking whether magnets in a brushless motor would detach at 800 RPM. Below is an explanation of this issue.

Generally speaking, under normal design and installation conditions, the magnets (typically arc shaped neodymium-iron-boron magnets) of brushless motors are nearly impossible to detach at 800 revolutions per minute (rpm), as this speed is extremely low and far below the threshold that would pose any risk.

In actual engineering cases, magnet detachment is rarely caused by excessive rotational speed but rather by poor manufacturing practices. These include incomplete adhesive curing, failure to degrease and polish bonding surfaces, or damaged magnet coatings leading to insufficient adhesion. Even at low rotational speeds, magnets may loosen or shift under vibration or temperature rise if the adhesive bond strength is inadequate.

Nickel Plated High Strength Curved Magnet

Additionally, temperature should not be overlooked. During prolonged operation, the coils and rotor of brushless motors may heat up to 80–120°C, which directly reduces adhesive strength. If low-temperature adhesive is used or heat dissipation near the magnets is poor, the bonding layer's performance degrades under high temperatures. Even at just 800 rpm, thermal cycling may cause magnet detachment or failure.

High-quality motors often employ more reliable structures, such as mechanical stop slots or steel sleeve wrapping. These designs can operate stably even at 20,000 rpm.

Therefore, as long as the adhesive meets specifications and temperatures remain within acceptable limits, the issue of magnets detaching at 800 RPM will not occur. Our company offers magnetic tiles (arc-shaped magnets) for brushless motors and radial multi-pole rotor magnetic rings. For pricing evaluations, please leave a message or contact us online with samples of similar dimensions.

Other articles on brushless motor magnets;

Brushless motor magnet arrangement and spacing

How to choose the magnet used inside a brushless motor?

Relation Between Hall and Pole Pair Number of Brushless Motor