It will be obvious from my book that I'm impressed with these. The video here is well worth watching.
- Fasten bolts or nut/bolt combinations.
- Get more accurate torque settings.
- Protect against settlement in the bolted material.
- Protect against the relaxation of the shaft.
- Protect against vibration & dynamic loads.
Buy an assorted box as a starter kit.
Not easy to get hold of but the originals nord-lock-wedge-lock/] are.