Use a sealing and cushioning washer to prevent leakage around fasteners on a plumbing fixture, vehicle brake system or hydraulic application. A rubber washer also reduces vibration and noise and is commonly used with roofing and siding fasteners. Bonded washers are made of silicone rubber with metal backing and combine strength and flexibility. Choose these sealing and cushioning washers from Grainger to prevent costly fluid leakages on plumbing fixtures and engines.