En8 d Plain Washer refers to a carbon steel grade commonly used in engineering and manufacturing. This is a simple flat washer without any special features like locking teeth or serrations. It is a medium-strength steel that is often used for applications requiring good tensile strength and toughness. The "d" might refer to the diameter of the washer and "EN8 means a plain washer made from EN8 steel with a diameter of 10 millimeters. En8 d Plain Washer is used to distribute the load of a threaded fastener, such as a bolt or nut, over a larger surface area and prevent damage to the material being fastened.