Bolts are typically used to fasten two or more objects together through pre-drilled holes. Washers are used to strengthen the connection by distributing the force that is being applied by the bolt over a broader area. Specialty washers are also available. Lock washers, for example, help prevent accidental loosening of the bolt. Nuts are threaded onto the bolt to tighten the connection and, like washers, come in a variety of types for a variety of applications.
Determine the correct size and type of bolt, nut and washer for your application. This will depend on the type of connection being made, the materials being used, the strength of the bolt, standards and regulations for the application and a variety of other factors.
Place the first washer on the shaft of the bolt. If a lock washer is required, it will be placed on the bolt followed by a second standard washer.
Align the holes for the joint you are connecting and push the shaft of the bolt through them. The washers should be pressed between the head of the bolt and the material of the joint.
Place the second washer, or set of washers, on the portion of the shaft of the bolt that is sticking out from the joint.
Thread the nut onto the shaft of the bolt by twisting clockwise. Hand-tighten the nut so that it is pressed against the washers.
Use an appropriately sized wrench to tighten the nut firmly against the washers.