M30 Spring Washer (Square) in A4 Stainless
Square Section Spring Washers are designed to help prevent loosening of bolted joints under vibration. Also know as Split Lock Washers and Split Ring Washers.
This type has a square section and is generally used with Socket Head Cap screws/bolts, manufactured to DIN 7980.
Where even distribution of load on the mating surface is the primary requirement an alternative spring washer or a flat washer would be a more suitable solution.
In addition Spring Washers do not offer protection for the material being fastened.