SUYU-Double Coil Spring Washers have been rigorously tested and approved by independent institutes as well as certification authorities. SUYU-Double Coil Spring Washers are used in numerous industries such as: energy, transportation, offshore, mining and quarrying, construction and bridge building, manufacturing and processing, ship building, forestry and agriculture, heavy vehicles, and military. Our washers are approved by several industry standards and specified by numerous international companies. Over the operational life cycle, our washers give increased operational reliability and lower maintenance costs while significantly reducing the risks of production stops, accidents and warranty claims.