Ways to protect threaded connections from self-tightening
- Locking with a lock nut. A lock nut is a second nut that is screwed onto the same bolt alongside the main nut and prevents it from self loosening by increasing the friction forces in the thread.
- Locking with self-locking nuts. Self-loosening is prevented by a nylon liner, beveled edges or a flange with serrations on the nut that increase the friction forces.
- Fastening with a spring split washer (grover), the compression of the bent ends of which increases the friction force.
- A resilient wavy washer mounted under the screw head creates the necessary force to increase friction in the threads.
- Control washers with slightly curved teeth that increase the grip between the contacting surfaces.
- Stopping with special washers. The washers with tendrils secure the nut to the workpiece or any protruding part on the workpiece surface. To fix the washer, bend the edge of the washer or its tendril all the way to the nut face or other part plane.
- Use of locking screws that rest against the threaded rod through the nut body.
- The coloring of the screw heads is designed to prevent self-tightening and to protect them from corrosion.
- The cotter pin is used for locking flats and slotted nuts with an adjustable cotter pin.
- Wire locks are used for screws and nuts with wire holes. The wire threaded into the hole is twisted in such a way as to create a torque in the direction of thread tightening.
- Pinning is used to lock special screws.
- We will use a spring to increase the friction force between the thread turns.
- Countersinking or tapping is used for countersunk screws and nuts. The core is struck in the spline area for a screw or in the thread area for a nut.
- Extension of the slotted screw end after screwing.
- Only use riveting when you do not need to remove the screws.