By Tony Li    Photo：CANVA

Section 232 refers to Section 232 of the Trade Expansion Act of 1962. This law grants the U.S. President the authority to impose tariffs or other trade restrictions on imports based on national security considerations.

Key Content:

According to Section 232, if certain imported goods are believed to threaten U.S. national security, the President can decide, based on an investigation, whether to impose tariffs or other trade measures on those products. These investigations are typically initiated by the U.S. Department of Commerce, which assesses the quantity, types, and potential national security implications of the imports, and may impose tariffs on imports that could affect national security. Based on past cases, the following are key industries affected by Section 232:

1. Steel Industry

• Impact: The U.S. has previously imposed tariffs on steel products under Section 232, arguing that large volumes of steel imports could threaten U.S. national security, particularly in defense and infrastructure sectors. This measure protected steel manufacturers and increased the competitiveness of domestic production.
• Scope: This has protected the U.S. steel industry and raised the price of imported steel, placing some cost pressure on industries that rely on steel.

2. Aluminum Industry

• Impact: Similar to the steel industry, the U.S. imposed tariffs on aluminum products under Section 232. Aluminum has significant strategic value in aviation, defense, and automotive sectors, leading the U.S. government to consider protecting the aluminum industry as crucial for national security.
• Scope: This benefited domestic aluminum producers but raised the price of imported aluminum, which could create higher costs for industries relying on aluminum, such as automotive manufacturing and aerospace.

Annual Adjustments to Section 232 Steel and Aluminum Tariffs

• 2018 (Trump’s First Term): A 25% tariff was imposed on imported steel, and a 10% tariff was imposed on imported aluminum.
• 2025 (Trump’s Second Term):

March: A 25% national security tariff on steel and aluminum.

June: Tariffs on steel, aluminum, and their derivative products were increased to 50%.

August: Expanded the scope to include about 407 additional steel and aluminum derivative products subject to a 50% tariff.

3. Automotive Industry

• Impact: Although the application of Section 232 in the automotive sector has been limited, the U.S. government threatened to impose tariffs on imported vehicles under Section 232, especially amid intense competition in the domestic automotive industry.
• Scope: If such measures were implemented, the cost of imported vehicles would rise, potentially affecting consumer purchasing decisions and making U.S. automakers face more challenges from the global market.

4. Aerospace Industry

• Impact: The aerospace industry is highly dependent on metals like steel, aluminum, and nickel, and when these key raw materials are affected by tariffs, aerospace companies may face rising costs. Particularly for military aviation and defense-related equipment, which are critical for national security, this could attract more scrutiny.

5. Energy Industry (Especially Oil and Gas)

• Impact: While Section 232 mainly targets metal products, certain energy-related products (such as oil pipelines and natural gas equipment) may also be included in investigations due to their relevance to national security. In the context of U.S. energy independence and energy security, the regulation of imported energy equipment may come under closer examination.

6. Machinery and Heavy Equipment Industry

• Impact: Many heavy machinery and equipment sectors rely on steel, aluminum, and other raw materials. These industries may face increased costs as a result of Section 232, which affects the availability and price of these essential raw materials.

7. Electronics and Semiconductor Industry

• Impact: Semiconductors and electronic products play important roles in many defense, energy, and high-tech sectors. Although these products are not directly impacted by Section 232, they could be affected if imported raw materials or components critical to national security are included in investigations.

8. Infrastructure Construction Industry

• Impact: Infrastructure projects (such as roads, bridges, pipelines, etc.) often require large quantities of steel and aluminum. As such, these industries are impacted by Section 232 policies, especially when rising import costs increase the overall project costs.

Comprehensive Impact:

• Protection of Domestic Industries: For U.S. industries like steel and aluminum, Section 232 provides protection by reducing foreign competition and dumping, enhancing the competitiveness of domestic production.
• Increased Costs: However, industries relying on these raw materials (such as automotive, aerospace, and construction) may face higher production costs due to the tariffs and import restrictions, which could impact product prices.
• International Trade Tensions: These trade restrictions often lead to retaliatory actions from trade partners, further escalating international trade tensions, particularly in today’s highly globalized economy.

Exemptions and Exceptions:

• Some products, such as household appliances made from U.S.-melted and cast steel and aluminum, may be exempt from tariffs.
• Countries like the UK and others may receive temporary exemptions or tariff quotas through trade agreements.
• Derivative products made from U.S.-melted and cast steel may also be exempt.

Conclusion:

The industries affected by Section 232 are primarily concentrated in heavy manufacturing, infrastructure construction, and high-tech sectors. These industries' supply chains are susceptible to disruptions caused by import tariffs or trade restrictions. Following the initial implementation of Section 232 in 2018, tariffs were significantly raised and product scope expanded in 2025. The primary aim is to protect U.S. national security, but its implementation has particularly impacted allied countries.

According to the U.S. Department of Commerce’s notice in the Federal Register, the Bureau of Industry and Security has established procedures to include more steel and aluminum derivative products within the scope of tariffs authorized by President Trump under Section 232. The deadline for submitting relevant inclusion requests is September 29. The information above reflects data available up until the publication of this article.

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