Hot Stamping Patents: Top Companies & Filing Trends 2026
- Filing has cooled since 2022. The peak year was 2022 at 282 records, and the 2026 count of 16 (partial year) sits well below the 2017 baseline of 240 — publication lag explains part of the drop but not the multi-year downward trend.
- The top 5 assignees hold 32.9% of the field. 1,180 of the 3,589 records in scope trace to five companies, with the top 10 combined reaching 39.3% — concentrated enough that a new entrant is filing into occupied claim space from day one.
- Heat treatment and alloy claims dominate. C21D (heat treatment of metals) appears on 39.6% of records and C22C (alloys) on 30.4%, while coating classes like B44C sit under 9% — a gap between core process claims and surface/decorative treatment claims.
What the hot stamping patent record shows
Hot stamping and press hardening patents cluster around a narrow set of process problems: how fast a blank cools, how a coating survives furnace transfer without oxide scale, and how a single part can carry both a hard martensitic zone and a ductile soft zone. The search underlying this page pulls 3,589 records published between 2015 and mid-2026 that combine those process terms with the core hot-forming vocabulary, so the set is weighted toward documents that discuss production variables rather than pure metallurgy.
Filing has been in steady decline since a 2022 peak, and the assignee ranking is already concentrated at the top with a long tail below it. That combination — falling filing volume plus early concentration — points to a field where the foundational process claims were staked out early and later entrants are filing narrower, defensive improvements around them.
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Filing trends and technology composition
Two views of the same 3,589-record set: how filing volume has moved year over year, and how those records distribute across IPC subclasses. Because a single record can carry several IPC codes, the technology shares add up to more than 100% of the record total.
A downward trend since the 2022 peak
Annual filings ran at 240 in 2017 and rose to a peak of 282 in 2022, then declined toward 16 in 2026 — a partial year, so the true 2026 figure will land higher once publication catches up, but the multi-year direction from 2022 onward is down rather than flat.
Heat treatment and alloy classes lead
C21D (heat treatment of metals) covers 39.6% of the 3,589 records, ahead of C22C alloys at 30.4% and B21D sheet-metal working at 26.4%. Coating and surface classes — C23C at 24.9%, B32B at 15.5%, and the smaller B41M, B44C and B23K groupings — describe a secondary cluster around protecting and joining the formed part rather than forming it.
Shares are the percentage of the 3,589 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Hot Stamping and Press Hardening with Eureka
This page is one run against one query. Ask Eureka your own question about hot stamping and press hardening and every answer comes back with the patent numbers behind it.
Try EurekaA representative filing and the most-cited prior art
Manufacturing method for hot stamping component having aluminium-silicon alloy coating, and hot stamping component
A manufacturing method for a hot stamping component having an aluminium-silicon alloy coating, and a hot stamping component, the method comprising machining an aluminium-silicon alloy-coated steel plate into a blank, then subjecting the blank to two-stage or three-stage step heating followed by hot stamping. The coating sits on at least one surface of the substrate.Filed by Baoshan Iron & Steel; published 2021-08-19 as US20210252579A1.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4854330A | Formed core catheter guide wire assembly | 287 |
| 2 | WO2001053113A1 | Optically variable security devices | 225 |
| 3 | WO2008053273A1 | Coated steel strips, methods of making the same, methods of using the same, stamping blanks prepared from the… | 182 |
| 4 | US20050128543A1 | Optically variable security devices | 173 |
| 5 | US5648165A | Hot stamp article for applying optically variable coating to substrates | 170 |
| 6 | US4044231A | Secure property document and method of manufacture | 150 |
| 7 | EP2737971A1 | Tailor welded blank, manufacturing method thereof, and hot stamped component using tailor welded blank | 137 |
| 8 | US4676857A | Method of making microwave heating material | 132 |
| 9 | US20040101676A1 | Optically variable security devices | 113 |
| 10 | US5165187A | Edge illuminated sign panel | 108 |
Citation counts reflect influence within the searched corpus and skew toward older documents; some of the highest-cited records here relate to hot-stamped decorative and security foil rather than automotive structural parts, reflecting shared IPC territory (B44C, B41M) rather than a single application.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the filing pattern means for strategy
The numbers point to a mature, concentrated core with specific openings on the edges rather than in the centre.
The core process is claimed by a small group
Five assignees account for 1,180 of the 3,589 records in scope. Filing a broad claim on basic cooling-rate or tailored-property control now means designing around whatever this group already holds.
Filing volume has turned down
The field peaked in 2022 and has declined every year since; several leading assignees show 0 filings or an 86-100% year-on-year drop in the most recent year, which is consistent with a slowdown rather than a reporting artefact alone.
Process claims outweigh surface-finish claims
Heat treatment (C21D) and alloy composition (C22C) claims are far more common than decorative or surface-finishing claims (B44C, B41M), even though several of the most-cited records in the set are decorative hot-stamping foil patents — a sign those citations come from an adjacent, older field rather than current activity.
China leads receiving-office volume
China's 868 filings outpace the United States (581), EPO (518), India (226), Japan (204) and WIPO/PCT (183), indicating that current production and process-improvement activity is being documented for the Chinese market first.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to hot stamping and press hardening, with the prior art for and against each one.
Assignee landscape and filing momentum
The ranked leaders (100 companies) trace a familiar shape for a mature process technology: a handful of steelmakers and automotive suppliers hold the largest blocks, with a long tail of single- or few-filing entrants below tenth place, where the count already drops to 37.
One steelmaker sets the pace
The leading assignee's 436 records dwarf the fifth-place count of 69, showing the concentration is front-loaded rather than spread evenly across the top group.
The ranking thins out fast
By tenth place, filing volume has fallen to 37 records — a steep drop from the leader's 436 — meaning most of the ranked 100 companies hold only a handful of filings each.
Steel-and-forming partnerships are the strongest links
Co-filing is limited to ten identified pairs, with the strongest — a steel producer and its metal-forming affiliate — sharing 22 records, and a steelmaker-and-research-arm pair sharing 6.
| Assignee | Recent year | YoY |
|---|---|---|
| ArcelorMittal SA | 3 | -86% |
| Voestalpine Stahl GmbH | 1 | — |
| Nippon Steel Corporation | 0 | -100% |
| NIPPON STEEL & SUMITOMO METAL CORP | 0 | — |
| Hyundai Steel Co., Ltd. | 0 | -100% |
| Baoshan Iron & Steel Co., Ltd. | 0 | -100% |
| Kobe Steel, Ltd. | 0 | -100% |
| Magna International Inc. | 0 | — |
Where to take this analysis
The dataset points to a concentrated, cooling field with specific gaps rather than an open frontier. The next steps depend on whether you are clearing a filing or scouting for licensing or acquisition targets.
Map claim scope against the top assignees
With 32.9% of records held by five companies, any new filing on core cooling-rate or tailored-property control should be checked claim-by-claim against this group before drafting.
Run a freedom-to-operate check in EurekaTrack the under-claimed branches
Hydrogen embrittlement mitigation and cycle-time reduction show thinner coverage than the core heat-treatment classes, which is where a narrower, defensible claim is more likely to issue.
Explore white space in EurekaCommon questions about hot stamping patents
Filing in this field is concentrated: the leading assignee alone accounts for 436 of the 3,589 records in scope, and the top five assignees combined hold 32.9% of all records. Beyond the top ten, which together hold 39.3% of the field, filing volume drops sharply, with the tenth-ranked assignee holding only 37 records. This shape is typical of steel producers and their automotive-supplier affiliates who staked out core process claims early and have continued filing incremental improvements since.
No — filing peaked in 2022 at 282 records and has declined in every year since, reaching 16 records in the partial 2026 year. Publication typically lags actual filing by around 18 months, so the most recent one or two years will always look artificially low and should not be read as a sudden stop. Even accounting for that lag, several major assignees show year-on-year drops of 86% to 100% in the latest year, which points to a genuine slowdown rather than a reporting gap alone.
The largest share of records, 39.6%, falls under IPC class C21D covering heat treatment of metals, followed by C22C alloys at 30.4% and B21D sheet-metal working at 26.4%. Coating and lamination classes such as C23C and B32B appear on roughly a quarter and a sixth of records respectively, describing the secondary cluster of work on protecting the formed part. Because a single patent can carry multiple IPC codes, these shares overlap and add up to more than 100% of the 3,589 records in scope.
Relative to the dominant heat-treatment and alloy classes, coverage thins out in areas like hydrogen embrittlement risk mitigation, cycle-time reduction during die transfer, and fine-grained control of the soft-zone gradient in tailored-property parts. These are documented in the search terms behind this dataset but do not show up as heavily claimed subclasses the way core cooling-rate and coating composition claims do. That gap is where a narrowly drafted claim is more likely to clear existing prior art, though any specific claim still needs individual clearance.
Not necessarily. Citation counts inside a searched patent corpus favour older documents simply because they have had more time to be cited, and several of the most-cited records in this dataset relate to decorative and security hot-stamping foil rather than automotive structural forming. A high citation count is a signal of historical influence within the corpus, not a measure of current commercial relevance, so it should be weighed alongside filing recency and assignee activity rather than read on its own.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.