Importers of HS 8507.10 (lead-acid storage batteries, of a kind used for starting pis) from Vietnam actually paid 18.7% on the taxed portion of the value in 2026-06 — 18.19% 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% → 18.7%, with the largest single step +12.3pp 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 18.7%, so the trade-war overlay added 15.2 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "8507.10", origin: "Vietnam") · see it at trimtabist.com/tariffs
HS 8507.10. The schedule base rate is 3.5%; importers from Vietnam actually paid 18.7% on the dutiable value in 2026-06 — the trade-war overlay added 15.2 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 3.5% (2023-07) → 18.7% (2026-06), largest single step +12.3pp in 2025-05.
Vietnam's lower duty (18.19% vs 38.32%) lets it price up to 17% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, China actually lands cheaper — $3.33/kg vs $3.75/kg (duty in, freight out).
2 Chapter-99 measures name Vietnam; 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 Vietnam · the whole tariff ledger · reproduce: tariff_story(hs: "8507.10", origin: "Vietnam") via /connect. Not customs or legal advice.