Internal teethed washers
Description
Internal teethed washers with geometry according to the standard DIN 6798 have teeth that extend inward from the inside edge of the washer and are recommended when the head of the bolt is smaller than the external diameter of the washer. They can guarantee a nice locking effect, in particular on non-flat bearing surfaces and are suitable for light application and soft bearing surface, such as mild steel and aluminium.
The teeth bite into the bearing surface and the underhead of the screw to oppose the loosening force.
Internal teethed washers are normally designed for use with bolt/nut assemblies involving fasteners of a property class less than 8.8.