https://www.mnpctech.com/casemodstore.html
https://www.superiorwasher.com/washers/7901/All-Washers.html
When you click this video clip, prepare to learn more about a most basic fastening material that is used in almost all fastening applications. The disc-shaped components known as washers have properties based on the material from which they are manufactured, that allow them to perform fastening functions as reliably as possible.
There are different types of washers and each type is designed to deliver a specific purpose and function. Spring and Belleville are two of such other popular types of fastening hardware aside from the standard type.