How is the locking feature of a fiber-type locknut achieved?

The locking feature of a fiber-type locknut is achieved by using an unthreaded fiber locking insert. This type of insert is typically made from a special fiber material that deforms when the nut is tightened, creating friction against the bolt threads. This friction is what prevents the nut from loosening due to vibrations or dynamic loads.

The design of the unthreaded fiber insert allows it to grip the threads of the bolt or stud without being actually threaded itself, providing a reliable and reusable locking mechanism. As the nut is turned, the fiber material compresses, enhancing grip and ensuring a secure fit that does not require excessive torque to maintain.

The other options relate to different locking mechanisms or techniques that are not applicable to fiber-type locknuts specifically. A threaded metal insert, for instance, generally pertains to locking nuts with an internal threading feature rather than a fiber insert. Excessive torque can damage components rather than provide a proper locking feature, and chemical bonding agents can create permanent locks but do not apply to the operation of fiber-type locknuts.