Washers are thin disk-shaped plates with holes that generally distribute the load of threaded fasteners. Normally washers are used in distributing load from screws and nuts. Washers can be made from metal and plastic. Bolted-joints require hardened steel washers, which helps in preventing loss of pre-load due to Brinelling. [readmore]
Washers and Gaskets are commonly mistaken for one, but these are developed for different functions all together. Galvanic corrosion is a problem that occurs when insulating steel screws from aluminium surfaces. Washers help in resisting galvanic corrosion during the process. Washers come in three types viz. Plain washers, Spring Washers and locking washers. Plain Washers help in spreading load and prevent damage to the fixable surface. Spring washers come with axial flexibility and prevent either fastening or loosening of bolts due to vibrations. Locking washers prevent fastening and loosening by preventing unscrewing of fastening device. Other washer types include fender washer, anchor plate or wall washer, and torque washer.