When the White House doubled Section 232 steel tariffs from 25% to 50% in mid-2025 — and then layered on further tightening in April 2026 — the political story wrote itself: America protects its steel industry. The financial story is messier. The same proclamation that handed domestic steel mills a protected price floor handed Caterpillar (CAT) a $1.5–1.8 billion cost headache in 2025 alone, ballooning toward an estimated $2.6 billion burden in 2026. The company that builds America turns out to be one of the biggest steel buyers in America, and the tariff wall hits both sides of that ledger.