Importers of HS 8507.10 (lead-acid storage batteries, of a kind used for starting pis) from Korea, South actually paid 15.4% on the taxed portion of the value in 2026-06 — 12.97% across everything shipped, taxed or not. Measured from official duty receipts, not the rulebook: the statutory MFN base rate on this code is 3.5%. Over the window the rate on the taxed portion moved 3.5% → 15.4%, with the largest single step +11.5pp in 2025-05. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is 3.5% — importers actually paid 15.4%, so the trade-war overlay added 11.9 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "8507.10", origin: "Korea, South") · see it at trimtabist.com/tariffs
HS 8507.10. The schedule base rate is 3.5%; importers from South Korea actually paid 15.4% on the dutiable value in 2026-06 — the trade-war overlay added 11.9 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 3.5% (2023-07) → 15.4% (2026-06), largest single step +11.5pp in 2025-05.
Korea, South's lower duty (12.97% vs 38.32%) lets it price up to 22.4% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, Korea, South actually lands cheaper — $2.73/kg vs $3.33/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 · reproduce: tariff_story(hs: "8507.10", origin: "South Korea") via /connect. Not customs or legal advice.