Shoulder washers, also known as insulating washers or step washers, are fasteners featuring a built-in flange or shoulder. They serve two main purposes: providing spacing and electrical insulation. These washers are commonly used in electronics, automotive, and machinery applications to prevent metal-to-metal contact, reduce vibration, and ensure proper alignment of components. Made from materials such as nylon, plastic, or fiber, shoulder washers offer excellent resistance to corrosion, wear, and electrical conductivity. This makes them ideal for insulating screws and protecting sensitive components.