A blade for a paper-cutting machine does not serve metalworking, woodworking, food processing, or agricultural functions, so it falls under the residual subheading 820890, which covers knives and cutting blades for machines or mechanical appliances not elsewhere specified. The subheading selection always follows the industry or application the blade is designed for.

Blades classified under 820830 that are imported as components of food-contact equipment may be subject to FDA review if they are part of a food-processing system subject to food-safety regulations. Importers should confirm whether the blades are presented as standalone parts or as part of a regulated food-processing machine, and consult a licensed customs broker or the relevant agency to determine applicable admissibility requirements.