What is the primary use of washers in fastening applications?

The primary use of washers in fastening applications is to distribute load over a larger surface area. When a fastener, such as a bolt or screw, is tightened, it exerts force on the material being fastened. Washers provide a larger bearing surface, which helps to spread that force evenly across the material. This distribution reduces the localized stress that can lead to material fatigue, stripping, or even failure.

In addition to load distribution, washers can also serve other purposes, such as providing a cushion to alleviate vibration, preventing damage to the surface materials, and serving as a barrier against moisture and corrosion when using specific materials. However, the key function remains the load distribution as it significantly enhances the integrity and longevity of the fastening assembly.