| 7304.29.50 | 75 | Having an outside diameter exceeding 406.4 mm | kg | | | |
| 7304.29.61 | 15 | Having an outside diameter not exceeding 114.3 mm: | | | | |
| 7304.29.61 | 15 | Having a wall thickness not exceeding 9.5 mm | kg | | | |
| 7304.29.61 | 30 | Having a wall thickness exceeding 9.5 mm | kg | | | |
| 7304.29.61 | 45 | Having an outside diameter exceeding 114.3 mm but less than 215.9 mm | kg | | | |
| 7304.29.61 | 60 | Having an outside diameter of 215.9 mm or more but not exceeding 406.4 mm | kg | | | |
| 7304.29.61 | 75 | Having an outside diameter exceeding 406.4 mm | kg | | | |
| 7304.31 | | Other, of circular cross section, of iron or nonalloy steel: | | | | |
| 7304.31 | | Cold-drawn or cold-rolled (cold-reduced): | | | | |
| 7304.31.60 | 10 | Suitable for use in boilers, superheaters, heat exchangers, condensers, refining furnaces and feedwater heaters | kg | | | |
| 7304.39.00 | 02 | Suitable for use in boilers, superheaters, heat exchangers, condensers, refining furnaces and feedwater heaters: | | | | |
| 7304.39.00 | 06 | Having an outside diameter of 190.5 mm or more but not exceeding 285.8 mm | kg | | | |
| 7304.39.00 | 08 | Having an outside diameter exceeding 285.8 mm | kg | | | |
| 7304.39.00 | 16 | Galvanized, having an outside diameter not exceeding 114.3 mm | kg | | | |
| 7304.39.00 | 24 | Having an outside diameter of 38.1 mm or more but not exceeding 114.3 mm: | | | | |
| 7304.39.00 | 24 | Having a wall thickness less than 6.4 mm | kg | | | |
| 7304.39.00 | 36 | Having a wall thickness less than 12.7 mm | kg | | | |
| 7304.39.00 | 40 | Having a wall thickness of 12.7 mm or more but less than 19 mm | kg | | | |
| 7304.39.00 | 44 | Having a wall thickness of 19 mm or more | kg | | | |
| 7304.39.00 | 48 | Having an outside diameter of 190.5 mm or more but not exceeding 285.8 mm: | | | | |
| 7304.39.00 | 48 | Having a wall thickness less than 12.7 mm | kg | | | |
| 7304.39.00 | 52 | Having a wall thickness of 12.7 mm or more but less than 19 mm | kg | | | |
| 7304.39.00 | 56 | Having a wall thickness of 19 mm or more | kg | | | |
| 7304.39.00 | 62 | Having an outside diameter exceeding 285.8 mm but not exceeding 406.4 mm: | | | | |
| 7304.39.00 | 28 | Having a wall thickness of 6.4 mm or more but not exceeding 12.7 mm | kg | | | |
