M8 Spring Washer (Rectangular) in Duplex 1.4462 Stainless - DIN 127B
Spring washer designed to help prevent loosening of bolted joints under vibration.
Also know as a Split Lock Washer and a Split Ring Washer.
This type has a rectangular section and is generally used on hexagon head bolted fixings, manufactured to DIN 127.
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.