Seal washers are used as sealing components in mechanical equipment and pipelines wherever fluids are present. They serve as sealing materials, both internally and externally. Seal washers are made from metal or non-metallic sheet materials, which are cut, stamped, or trimmed to form. They are used for sealing connections between pipes and for sealing connections between components of machinery and equipment. They can be categorized into metallic and non-metallic seal washers. The metallic types include copper washers, stainless steel washers, iron washers, aluminum washers, etc., while the non-metallic types include asbestos washers, non-asbestos washers, paper washers, rubber washers, and more.