Ferritic Stainless Steel for Automotive Exhaust Patents: Top Companies 2026
Ferritic Stainless Steel for Automotive Exhaust Patents
42.2% of all 4,851 records sit with just five assignees — filing here means designing around an occupied top tier, not an open field. Volume peaked at 179 records in 2017. The 2021→2024 window, the most recent span with complete publication, shows filings falling from 100 to 61 — a 39% decline. Treat 2025 and 2026 figures as provisional given the typical 18-month publication lag.
- 1JFE STEEL CORP15.7%
- 2NIPPON STEEL CORPORATION8.0%
- 3NIPPON STEEL STAINLESS STEEL CORP7.0%
- 4SHELL OIL CO5.9%
- 5NIPPON STEEL & SUMIKIN STAINLESS STEEL CORP5.7%
See the full ferritic stainless steel for automotive exhaust analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions on this landscape
Who are the leading patent holders in ferritic stainless steel for automotive exhaust?
The assignee ranking is led by one steelmaker with 761 records, well ahead of the fifth-ranked filer at 276. The top five assignees together account for 2,048 of the 4,851 records in scope, or 42.2% of the field, so filing activity is concentrated among a small group of steel producers rather than spread evenly. Automakers appear mainly through co-assignee filings alongside these steelmakers rather than as independent top filers.
Is filing activity in this space growing or shrinking?
Filing peaked in 2017 at 179 records and has trended down since. The clearest comparable measure is 2021 to 2024, the last window unaffected by publication lag, where filings fell 39% from 100 to 61. Readers should treat 2025 and 2026 figures as still filling in, since publication typically lags actual filing by around eighteen months, but the multi-year decline through 2024 is real.
What technical areas does this patent set actually cover?
Records are classified predominantly under C22C (alloys, 63.5% of records) and C21D (heat treatment, 33.4%), meaning most claims concern the steel’s composition and processing route rather than the exhaust assembly itself. Exhaust-specific classification under F01N covers only 7.6% of records, and welding/brazing under B23K covers 4.7%. This split suggests the exhaust-hardware and joining layers carry comparatively less claim density than the base alloy chemistry.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Ferritic Stainless Steel for Automotive Exhaust covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.