Grades 304 and 316 (and their low-carbon 'L' variants) dominate commercial trade, with duplex grades like 2205 used in more demanding corrosive environments. While the SITC heading does not subdivide by grade, the HTS schedule does, and antidumping scope rulings have sometimes turned on alloy composition — so importers should confirm that the specific grade and chemistry of their flanges fall within or outside any active order's scope.

Most industrial buyers require material test reports (MTRs) certified to ASTM A182 or equivalent standards, along with dimensional compliance with ASME B16.5 or B16.47 for pressure-class flanges. For pharmaceutical and food-grade applications, surface finish certifications and traceability to heat numbers are also standard requirements.