A metal washer is a small, flat, circular piece of metal with a central hole. It is commonly used in machinery and construction for various purposes. Washers can serve as spacers, preventing components from coming into direct contact, or as shock absorbers, distributing the load from screws or bolts to prevent damage to the joined materials. The central hole allows the screw or bolt to pass through easily.

The manufacturing of metal washers involves various processes to ensure their strength and durability under stress. While several materials can be used, the most common are galvanized carbon steel and stainless steel. Due to the diversity in materials and shapes, there are numerous types of washers available. Plain washers are simple and flat, while spring washers can flex under pressure. Lock washers have designs that prevent screws from loosening. Additionally, there are specialized washers designed for specific applications.