FINE U-NUT® shaft nut

FINE U‑NUT® shaft nuts are used to fasten bearings and other machine parts on shafts. They are classified as mechanical installation methods and offer the advantage of easy bearing replacement. For instance, complex shaft preparation is unnecessary for servicing.

Rotating shafts can cause shaft nuts to loosen. Consequently, shaft nuts must be used with a nut locking element to ensure that the application is safe and reliable.

This is where the FINE U-NUT® advantages come in: The FINE U-NUT® incorporates a flexible metal ring that presses against the thread as the nut is screwed on. The metal ring produces a controlled friction lock on the thread. The friction lock is strong enough to prevent the connection from coming loose at constant tightening torques.

The FINE U‑NUT® was developed to reduce overall costs when installing bearings and improve the quality of the connection.

Usually conventional shaft nuts must be secured to the shaft with an additional locking element. This additional locking element must prevent the nut from coming loose, particularly at high rotational speeds. Yet at the same time this locking element must not compromise the accuracy of the threaded joint or its transmission of the forces that occur. Design and installation with an additional locking element are more complex and introduce an additional source of error.

Locknuts only provide temporary locking. Circlip constructions and tooth lock washers with locking tabs and keyway, or bow shackles and securing plates are laborious to install and often fail to provide adequate axial fixation. If service is required, time-consuming dismantling may be necessary.

The FINE U NUT® eliminates the need for additional locking elements and the associated costly lathing and milling tasks required to create a keyway on the shaft. In addition, no extra time-consuming design or installation tasks are required.