| 2412 | Nitrogenous fertilizer materials, manufacturing | |
| 2412 | Nitrogenous fertilizers, made by mixing purchased materials | |
| 2429 | Nitroglycerin explosive materials, manufacturing | |
| 2411 | Nitrophenol, manufacturing | |
| 2411 | Nitrosated hydrocarbon derivatives, manufacturing | |
| 2411 | Nitroso dyes, manufacturing | |
| 2429 | Nitrostarch explosive materials, manufacturing | |
| 2411 | Nitrous ether, manufacturing | |
| 2411 | Nitrous oxide, manufacturing | |
| 2423 | N-methylpiperazine, manufacturing | |
| 1711 | Noils, wool and similar animal fibre, manufacturing | |
| 5121 | Noils, wool, wholesale | |
| 2520 | Noise protectors, personal, manufacturing | |
| 7422 | Non destructive testing services | |
| 1553 | Non-alcoholic beer, brewing | |
| 5110 | Non-alcoholic beverages, wholesale agents and brokers | |
| 1552 | Non-alcoholic wine, manufacturing | |
| 2430 | Non-cellulosic fibres and filaments, manufacturing | |
| 2430 | Non-cellulosic filament yarn, manufacturing | |
| 2430 | Non-cellulosic staple fibres and filaments, manufacturing | |
| 2692 | Nonclay refractories (e.g., block, brick, mortar, tile), manufacturing | |
| 3120 | Non-current carrying plastics conduit, manufacturing | |
| 1520 | Non-dairy creamers, dry, manufacturing | |
| 1520 | Non-dairy creamers, liquid, manufacturing | |
| 6599 | Nondeposit trust companies | |
| 2411 | Nonene, made from refined petroleum or natural gas liquids | |
| 1520 | Nonfat dry milk, manufacturing | |
| 2891 | Non-ferrous (except copper and aluminum) forgings, unfinished, made from purchased non-ferrous metal | |
| 2720 | Non-ferrous alloys (except aluminum, copper), made from purchased metals | |
| 2720 | Non-ferrous alloys, made in primary smelting and refining mills (except aluminum) | |
| 2732 | Non-ferrous metal (except aluminum, copper) castings (except die-castings), manufacturing | |
| 2732 | Non-ferrous metal (except aluminum, copper) foundries (except die-castings) | |
| 2720 | Non-ferrous metal (except aluminum, copper) powder, paste and flakes, made from purchased metals | |
| 2720 | Non-ferrous metal (except aluminum, copper) shapes, made by rolling, drawing and extruding purchased metal | |
| 2720 | Non-ferrous metal (except aluminum, copper) wire, made in wire drawing plants | |
| 2720 | Non-ferrous metal (except aluminum, copper), recovering from scrap | |
| 5142 | Nonferrous metal (except precious) (e.g., sheets, bars, rods), wholesale | |
| 5110 | Non-ferrous metal and metal products, agents and brokers | |
| 2732 | Non-ferrous metal castings (except die-castings), manufacturing | |
| 2732 | Non-ferrous metal die-casting foundries | |