Metric A2 Stainless Steel (18-8 Series) Fender Washers are round thin flat washers with a larger outside diameter than standard flat washers of the same bolt size. They are used when a large washer diameter is- needed to increase surface area and prevent fastener pull-through.
A2 Stainless Steel (equal to 18-8 SS) offers effective resistance to corrosion in damp environments and exterior applications.