Customs classification of steel and aluminum products concerning US tariffs

The customs classification of steel and aluminum products in the customs tariff is a central challenge for internationally active companies. Especially with the reinstatement of the full Section 232 tariffs by the US government in February 2025, the precise classification of these products is once again in focus. Incorrect or inaccurate customs tariff numbers can lead not only to financial adjustments but also to delays in customs clearance or even legal consequences.

Section XV: Base Metals and Articles of Base Metals

The basis for the customs classification of steel and aluminum products is found in Section XV of the Harmonized System (HS). This section includes iron and steel (Chapter 72), products thereof (Chapter 73), aluminum (Chapter 76), as well as various other base metals.

Key Principles of Customs Classification in These Chapters

Material Composition Decides

According to the Notes 5 and 6 to Section XV and Note 1 to Chapter 72, alloys are generally classified according to the predominant metal by weight. This is particularly true for mixtures of different base metals.

For example, goods made of (predominantly) brass are classified as products of copper under Chapter 74 due to the predominant copper content.

Shape and Processing Are Crucial

The correct classification depends not only on the material but also on the shape and processing state of the product, according to Note 9 to Section XV. Several factors are decisive here:

Solid vs. Hollow Products

• Bars, wires, and profiles made of steel or aluminum fall into their headings depending on shape and production process.

• Tubes with a continuous cavity (round, oval, square, rectangular, triangular, or another regularly curved polygon) and uniform wall thickness are classified in different headings than solid bars.

Flat Products – Sheets, Strips, and Foils

• Solid flat products are flat pieces of metal with a rectangular or square cross-section, but they may also have slightly rounded edges or a special shape with two curved and two straight, parallel sides.

• If they are rectangular or square, their thickness must not exceed one-tenth of their width.

• If they have a different shape, they cannot be considered products covered by another heading.

• These flat products also include sheets, strips, and foils with patterns such as grooves, diamonds, or waves, as well as with perforated, corrugated, polished, or coated surfaces, provided these treatments do not make them special products that need to be classified in another heading of the nomenclature.

Hot- vs. Cold-Rolled Products

The shaping of metal can generally be divided into two categories: hot forming and cold forming. But what is the difference?

Hot Forming (at high temperatures, often around 900 °C)

→ Hot Rolling: Metal is rolled at high temperatures to the desired shape.

→ Forging: Metal is hammered or pressed into a new shape.

→ Hot Drawing: Bars, tubes, or profiles are drawn through a die to change their shape.

→ Hot Die Forging: Mass production by pressing in special molds.

Cold Forming (at room temperature, below the recrystallization temperature)

→ Cold Rolling: Metal is rolled at room temperature – results in a smoother surface.

→ Cold Die Forging: Cold variant of hot die forging.

→ Cold Extrusion: Metal is pressed into a closed mold under high pressure.

→ Wire Drawing & Rod Drawing: Wire rods or bars are drawn through dies to deform them.

Differences at a Glance

• Cold-manufactured products are smoother, have tighter dimensional tolerances, and a deformed grain structure.

• Hot-manufactured products have a rougher surface, greater tolerances, and a more uniform grain structure due to recrystallization.

• Cold-fabricated metals are harder and stronger, but lose some hardness through heat treatment.

• Hot-rolled products can be refined with a light cold pass (“skin pass”) but remain hot-rolled.

Additional Processing and Processing Depth

Goods with drillings, cutouts, or more complex shapes might be classified as “goods thereof,” which can shift them into Chapter 73 (steel goods) or 76 (aluminum goods).

Special Features in the Classification of Cermets

These microscopically heterogeneous materials made of metals and ceramics are subject to special classification rules and are separately covered under HS heading 8113.

Section 232: US Tariffs on Steel and Aluminum

As early as 2018, the Trump administration imposed tariffs on imports of steel and aluminum into the USA to protect the domestic industry from overcapacity and subsidized imports – especially from China. The tariffs originally stood at 25% for steel and 10% for aluminum.

With the recent decision in February 2025, these measures were further tightened:

• The tariff on aluminum was increased from 10% to 25%.

• The tariff on steel at 25% is reintroduced after a suspension under US President Biden.

• All existing exemptions for countries such as the EU, Canada, and Japan have been eliminated.

• Import controls have been tightened, especially through the “Melted and Poured” principle, which requires that steel products must have been melted and poured in the country of origin to be considered manufactured there.

• Stricter controls against false classification have been introduced to prevent circumventions of the tariffs.

Challenge for Companies: Accurate Classification Is Necessary

Considering the tightened trade regulations, companies are faced with the challenge of classifying their products correctly to avoid high import duties or even customs penalties. The correct classification determines whether a product falls under the Section-232 tariffs or possibly benefits from a more favorable treatment through a specific HS-heading.

An example: Aluminum sheets of heading 7606 are subject to the tariffs. However, if they are further processed or given an additional coating, another classification may apply, which may not fall under Section 232. The difference can have significant cost implications.

Conclusion

The current tightening of US trade measures with tariffs of 25% on steel and aluminum products shows: Precise customs classification is of strategic importance for companies. Choosing the right HS-heading can not only save costs but also minimize delays and legal risks.