The curvy, spring-like shape adds a small amount of tension to prevent nuts and screws from backing out due to mild vibration. These washers also flex slightly to compensate for uneven surfaces. While more secure than a standard flat washer, these have the least amount of gripping power of all our lock washers. They are best suited for electrical panels, light fixtures, and other light duty assemblies. These washers hold their shape when untightened, so you can reuse them a handful of times without losing strength.

With a grip that's second only to wedge lock, these washers stop nuts and screws from wiggling loose under constant, vigorous vibration. They are ideal for engines, turbines, generators, and other heavy duty equipment. Similar to a spring, they flatten under pressure to add tension between mating surfaces. As long as the washers aren't deformed or otherwise damaged, you can reuse them indefinitely without losing locking strength. Also known as conical washers and Belleville washers.

Stack multiple washers in the same direction to double or triple how much weight they can bear. Stack washers in opposite directions for better deflection, which means they compress further and withstand more shock and movement without loosening.