Compared to standard all purpose type 18-8 or 304 stainless steel washers, these type 316 stainless washers have superior resistance to rust or corrosion. Type 316 must be used for any saltwater or chemical application. Fender washers offer over-sized outside diameters for covering large holes or for use as spacers and levelers. Each Marine Bolt Supply pack is custom labeled and professionally heat sealed in reliable poly bags for safe shipping and use.