About 316 "Marine Grade" Stainless Steel
If a job requires greater corrosion resistance than grade 304 can provide, grade 316 is the 'next step up'. Grade 316 has virtually the same mechanical, physical and fabrication characteristics as 304 with better corrosion resistance, particularly to pitting corrosion in chemical environments. Grade 316 (UNS S31600) is the second most popular grade in the stainless steel family. It accounts for about 20% of all stainless steel produced.