This countersunk washer is made of 18-8 stainless steel and has a bright (uncoated) finish. It meets the standards for AMPG 2002 FIN.04, ASTM A582 industry standards. This countersunk washer also has the following resistance properties: chemicals resistant, corrosion resistant, dye resistant, food resistant, nitric acid resistant, and it is designed for use with flat and oval head screws and is for screws sized #8.