A spring washer, also known as a disc spring or Belleville washer, is a mechanical component designed to apply a preload or maintain tension between two surfaces. It provides elasticity, which helps absorb vibrations, compensate for loosening caused by thermal expansion or contraction, and distribute load evenly, ensuring a secure connection in bolted assemblies.

Spring washers work by exerting a continuous force on the fastener assembly due to their curved or conical shape. When compressed, they store energy and apply tension to maintain tightness, preventing nuts or bolts from loosening under dynamic loads, vibrations, or thermal changes.

Spring washers are typically made from high-strength materials such as stainless steel, carbon steel, alloy steel, or phosphor bronze. These materials offer excellent elasticity, corrosion resistance, and durability, allowing the washer to perform effectively in various environments, including harsh industrial settings.

Common types of spring washers include Belleville washers, wave washers, crescent washers, and split lock washers. Each type is designed for specific applications, offering varying levels of load distribution, tension, and vibration resistance based on the assembly's requirements.

Spring washers should be used in applications where maintaining tension, preventing loosening, or reducing vibration is critical. Examples include automotive assemblies, machinery, electrical systems, and construction equipment. They are particularly valuable in dynamic or high-vibration environments.