Spring washers, needless to say, you should know very common. Standard GB/T?93, GB/T?859? is the most commonly used:
Elastic washers, there are saddle-shaped elastic washers and wave-shaped elastic washers.
GB/T?860?saddle-shaped elastic washers:
GB/T?955?wave-shaped elastic washers:
Wave-shaped elastic washers, there are many similar non-standard products on the market