| 331110 |
Tube rounds, iron or steel, made in iron and steel mills |
| 331110 |
Tube, iron or steel, made in iron and steel mills |
| 331110 |
Tubing, seamless steel, made in iron and steel mills |
| 331110 |
Tubing, wrought iron or steel, made in iron and steel mills |
| 331110 |
Well casings, iron or steel, made in iron and steel mills |
| 331110 |
Wheels, car and locomotive, iron or steel, made in iron and steel mills |
| 331110 |
Wire products, iron or steel, made in iron and steel mills |
| 331110 |
Wrought iron or steel pipe and tubing made in iron and steel mills |
| 331210 |
Boiler tubes, wrought, made from purchased iron |
| 331210 |
Conduit, welded and lock joint, made from purchased iron or steel |