Importers of HS 3910.00 (silicones in primary forms) from Japan actually paid 12.97% 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%. Over the window the rate on the taxed portion moved 3% → 12.97%, with the largest single step +11pp in 2025-08. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is 3% — importers actually paid 12.97%, so the trade-war overlay added 10 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "3910.00", origin: "Japan") · see it at trimtabist.com/tariffs
HS 3910.00. The schedule base rate is 3%; importers from Japan actually paid 12.97% on the dutiable value in 2026-06 — the trade-war overlay added 10 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 3% (2023-07) → 12.97% (2026-06), largest single step +11pp in 2025-08.
Japan's lower duty (12.97% vs 37.97%) lets it price up to 22.1% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, China actually lands cheaper — $2.55/kg vs $9.18/kg (duty in, freight out).
12 Chapter-99 measures name Japan; 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 Japan · the whole tariff ledger · reproduce: tariff_story(hs: "3910.00", origin: "Japan") via /connect. Not customs or legal advice.