Never - Seez Pure Nickel Special and Nickel Nuclear Grade are superior, high temperature, extreme pressure anti-seize compounds. They contain flake particles of pure nickel, graphite and other additives in a special grease carrier found to enhance anti-seize performance. While the same high quality product as Pure Nickel Special, Nickel Nuclear Grade is specially tested and certified pure for use in nuclear power plants. Each production lot of Nuclear Grade is tested for contaminants of sulfur, halogens and low-melt metals. Each container of Nuclear Grade is labeled with the lot and test report number to certify purity. Both products are recommended for use when applications prohibit the presence of copper, especially when chemical resistance is required.