This 5/16 x 5/8 x .05 flat washer is made of 18-8 stainless steel, making it resistant to corrosion and rust. It is designed to distribute the load of a bolt or screw evenly over a surface, preventing damage to the material. This washer is commonly used in a variety of applications, including construction, automotive, and manufacturing. Its small size and thickness make it suitable for use in tight spaces or where a low profile is required.