| 2922 | Nail guns, hand held power-driven, manufacturing | |
| 2922 | Nail heading machines, manufacturing | |
| 2424 | Nail polish removers, manufacturing | |
| 2424 | Nail polishes, manufacturing | |
| 9302 | Nail salons | |
| 2022 | Nailed-laminated lumber beams, manufacturing | |
| 2922 | Nailers and staplers, hand held power-driven, manufacturing | |
| 2899 | Nails, brads and staples, made from purchased wire | |
| 2899 | Nails, iron or steel, made in wire drawing plants | |
| 2720 | Nails, made in aluminum wire drawing plants | |
| 2899 | Nails, made in non-ferrous (except aluminum, copper) wire drawing plants | |
| 2899 | Nails, wire, manufacturing | |
| 2899 | Name plate blanks, metal, manufacturing | |
| 9500 | Nanny housekeeper | |
| 2429 | Napalm, manufacturing | |
| 5141 | Naphtha (except bulk stations and terminals), wholesale | |
| 2411 | Naphtha, made by distillation of coal tar | |
| 2320 | Naphtha, made in petroleum refineries | |
| 2411 | Naphtha, solvent, made by distillation of coal tar | |
| 2411 | Naphthalene sulfonic acid, manufacturing | |
| 2411 | Naphthalene, made by distillation of coal tar | |
| 2411 | Naphthalene, made from refined petroleum or natural gas | |
| 2411 | Naphthalene, made from refined petroleum or natural gas liquids | |
| 2320 | Naphthalene, made in petroleum refineries | |
| 2411 | Naphthenic acid soaps, manufacturing | |
| 2411 | Naphthenic acids, made from refined petroleum or natural gas | |
| 2320 | Naphthenic acids, made in petroleum refineries | |
| 2411 | Naphthol, alpha and beta, manufacturing | |
| 2411 | Naphtholsulfonic acids, manufacturing | |
| 9301 | Napkin, laundered, supply service, on contract basis | |
| 2109 | Napkins (i.e., table), paper, made from purchased paper | |
| 1721 | Napkins, made from purchased fabrics | |
| 5139 | Napkins, paper, wholesale | |
| 2109 | Napkins, sanitary, made from purchased paper stock | |
| 1729 | Napkins, sanitary, textile wadding, manufacturing | |
| 2926 | Napping machinery, textile, manufacturing | |
| 1712 | Napping textile fabrics | |
| 1712 | Napping textile fabrics, for the trade | |
| 1110 | Naptha content from natural gas, recovery of | |
| 5139 | Narcotic medicines, wholesale | |