Section 232 steel & aluminum tariffs explained

If you import anything made of steel or aluminum — or containing meaningful amounts of it — Section 232 is a line item you cannot ignore. It's a different legal mechanism from the Section 301 China tariffs, it attaches to the material rather than a single country, and it reaches beyond raw metal into a long list of derivative products. Here's how it works and how to tell whether it hits your goods.

What Section 232 is

Section 232 of the Trade Expansion Act of 1962 lets the President impose import restrictions on goods found to threaten national security, following an investigation by the Department of Commerce. In 2018 Commerce found that steel and aluminum imports threatened national security, and the President imposed additional tariffs by proclamation — 25% on steel and 10% on aluminum at the outset. Those measures have been adjusted, extended and expanded since.

What it covers

• Primary steel and aluminum articles (the mill products themselves).
• A growing list of derivative products — items made substantially from covered metal.
• Coverage is defined by specific HTS numbers listed in Chapter 99 provisions.
• Scope and rates are set by presidential proclamation and modified over time.

Why derivatives matter to normal importers

You might not think of yourself as a metals importer, but if you bring in, say, steel wire shelving, aluminum extrusions, or fasteners, the derivative lists can pull your product into Section 232. That means the tariff applies even though your business has nothing to do with the steel industry — and it stacks on top of your base HTS rate and any Section 301 duty.

How it stacks with other tariffs

Section 232 is ad valorem and adds to your bill alongside the base duty and any Section 301 tariffs. A Chinese-origin steel derivative, for example, could carry its base HTS rate plus a Section 301 duty plus a Section 232 duty — three layers on the same customs value. This is exactly why an accurate landed-cost estimate has to resolve every applicable Chapter 99 measure, not just the headline rate.

How to check your exposure

1. Classify your product to its exact 10-digit HTS line.
2. Check whether that line appears on a Section 232 derivative list in Chapter 99.
3. Confirm the current rate and any country exclusion or quota for your origin.
4. Add it to your base duty and any Section 301 duty for the true landed cost.

Where to verify

The primary sources are the Commerce Department's Section 232 investigations and the presidential proclamations that set the rates and product lists, cross-referenced against the HTS Chapter 99 provisions. Because this measure has been modified many times, always confirm the current rate and scope rather than relying on the 2018 figures.