Despite what you may believe about the properties of metal, bolts are actually elastic. It’s not quite Stretch Armstrong dramatic, but when you tighten a critical bolt to specs, you’re actually pulling it beyond its original length. Based on the quality of steel used in the fastener, the diameter of the fastener and how far you stretch it, the load or force applied to the joint (the two pieces being fastened together) changes.
Andrew Markel covers how suspension component fasteners are secured using mechanical attachment methods like castellated nuts, nyloc nuts and torque-to-yield fasteners. He also discusses chemical solutions like thread locking compounds. Sponsored by Auto Value and Bumper to Bumper.
The desired result of tightening a fastener is to obtain a proper clamping force between parts. The clamping force prevents loosening when the vehicle is in use and external forces act on the clamped parts. All fasteners have a specified torque. The method used for a particular application is determined by engineering and specified in the service information. It is necessary to apply the fastener torque to the specific fastener identified.