Importers of HS 8537.20 (for a voltage exceeding 1,000 v) from Korea, South actually paid 9.88% on the taxed portion of the value in 2026-06 — 9.88% across everything shipped, taxed or not. Measured from official duty receipts, not the rulebook: the statutory MFN base rate on this code is 2.7%. Over the window the rate on the taxed portion moved 2.7% → 9.88%, with the largest single step +6.4pp in 2025-04. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is 2.7% — importers actually paid 9.88%, so the trade-war overlay added 7.2 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "8537.20", origin: "Korea, South") · see it at trimtabist.com/tariffs
HS 8537.20. The schedule base rate is 2.7%; importers from South Korea actually paid 9.88% on the dutiable value in 2026-06 — the trade-war overlay added 7.2 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 2.7% (2023-07) → 9.88% (2026-06), largest single step +6.4pp in 2025-04.
Korea, South's lower duty (9.88% vs 37.08%) lets it price up to 24.8% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, China actually lands cheaper — $12.75/kg vs $19.19/kg (duty in, freight out).
2 Chapter-99 measures name Korea, South; scope mapping is partial (several annexes are PDFs) — absence never means exemption. They do not sum, and some are product-specific — the collected rate above is the composed truth.
All goods from South Korea · the whole tariff ledger · 2 CBP rulings cite this code · reproduce: tariff_story(hs: "8537.20", origin: "South Korea") via /connect. Not customs or legal advice.