Tailored Tempering Patents: Leaders, Trends & White Space 2026
- 80.3% concentration. The top 5 of 20 ranked assignees hold 159 of 198 records in scope (80.3%), with a long tail below tenth place at just 4 records.
- Filings up 143%. Annual filings rose from 14 in 2021 to 34 in 2024, the last year publication lag lets us read reliably.
- Heat treatment dominates the claim map. C21D (heat treatment of metals) appears in 40.9% of records, ahead of B21D sheet-metal working at 34.3% and B62D motor vehicle structures at 29.3%.
Filing growth compares 2021 (14 records) with 2024 (34) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 198 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Tailored tempering and partial hardening describe processes that create a deliberate microstructure gradient within a single formed part — hard, high-strength zones next to softer, more ductile zones — usually by controlling die temperature zoning or cooling rate during hot forming. The approach matters most in automotive body structures, where a single stamped component needs to absorb crash energy in one region while remaining formable or weldable in another. This dataset covers 198 published records filed or published between 2015 and mid-2026, spanning heat treatment, sheet-metal working and alloy composition claims.
Because publication lags filing by roughly 18 months, the most recent one to two years in any trend understate real filing activity — 2024 is the last year that can be read as a complete picture.
Filing trend and technology composition
Two views of the same 198-record dataset: how filing activity has moved year over year, and which IPC subclasses carry the claims.
Filing trend, 2017–2026
Filings grew from 12 in 2017 to a peak of 34 in 2024, including a 143% rise from 2021 (14) to 2024 (34). 2025 and 2026 figures are still filling in under normal publication lag and should not be read as a slowdown.
IPC subclass composition
C21D (heat treatment of metals) leads at 40.9% of the 198 records, followed by B21D sheet-metal working at 34.3%, B62D motor vehicles and steering at 29.3%, and C22C alloys at 26.3%. Records can carry multiple classes, so these shares sum to more than 100%.
Shares are the percentage of the 198 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Tailored Tempering and Partial Hardening with Eureka
This page is one run against one query. Ask Eureka your own question about tailored tempering and partial hardening and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
US10378089B2 — Method and device for partially hardening semifinished products
Methods for using a mold to partially harden semifinished products comprised of hardenable steel, involving heating regions of the product above an AC1 temperature, positioning the product in a mold, positioning an active mold cooling element adjacent to or in contact with the heated regions, and cooling those regions at a defined rate to produce a hardened microstructure in the cooled zones while leaving adjacent regions softer.Assigned to Thyssenkrupp Steel Europe, published 2019-08-13.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4161090A | Post assembly and method | 96 |
| 2 | US20180318922A1 | Method for the economic manufacturing of metallic parts | 95 |
| 3 | WO2017077137A2 | Method for the economic manufacturing of metallic parts | 82 |
| 4 | WO2004033774A1 | Process for making a monofilament-like product | 34 |
| 5 | US20070269654A1 | Process for Making a Monofilament-Like Product | 32 |
| 6 | US20120021216A1 | Process for making a monofilament-like product | 22 |
| 7 | WO2017077137A9 | Method for the economic manufacturing of metallic parts | 19 |
| 8 | US20200190611A1 | Press-hardened welded steel alloy component and method of manufacturing | 14 |
| 9 | US20170314088A1 | Zinc-coated hot formed steel component with tailored property | 12 |
| 10 | EP3156506A1 | Partial radiation heating method for producing press hardened parts and arrangement for such production | 10 |
Citation counts favour older filings and are a signal of influence within this searched corpus, not a measure of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
The concentration, growth and citation patterns each carry a different implication for where a new filing would actually sit.
Claim space is tightly held at the top
Five assignees account for 159 of the 198 records in scope, an 80.3% share, while the tenth-ranked assignee holds only 4. A new entrant is filing into a field where the core process claims — heating above AC1, zoned mold cooling, defined cooling rates — are already staked out by a handful of steel and forming specialists.
Activity accelerated sharply through 2024
Annual filings more than doubled between 2021 and 2024, the last year unaffected by publication lag. That growth sits mostly with the same leading assignees rather than a wave of new filers, since the ranked list still tops out at 20 companies.
Heat treatment claims outweigh forming claims
C21D outpaces B21D sheet-metal working (34.3%) and B62D vehicle structures (29.3%), suggesting the thermal/metallurgical control side of the process is more heavily claimed than the tooling or part-geometry side. Coating (C09D, 6.6%) and polymer (C08F, 5.6%) classes appear far less often, marking lighter-claimed adjacent branches.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to tailored tempering and partial hardening, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| DSM IP Assets B.V. | VEILLAT CYRIL DAVID | 1 |
| DSM IP Assets B.V. | DIRKS CHRISTIAAN HENRI PETER | 1 |
Only 2 co-assignee pairs appear across the dataset, both involving the same DSM entity — most filings here are single-assignee, with little sign of joint development partnerships.
Who is filing, and who has gone quiet
The ranked leaders are almost all steel producers and forming-equipment makers; recent-year momentum shows even the top filers pulling back from 2024 levels.
One steel producer holds nearly a third of the field
The leading assignee's 73 records dwarf the fifth-place total of 10, indicating a single company's process and metallurgy claims dominate the freedom-to-operate picture for anyone forming hardenable steel with zoned die cooling.
Even the leader's filing pace has cooled
The top-ranked assignee dropped to 4 records in the latest year, an 81% year-on-year fall, while several mid-ranked names show zero latest-year filings. Given publication lag, this reads as a pause rather than exit, but it opens a filing window for challengers.
A long tail below the top 10
The tenth-ranked assignee holds only 4 records, and the ranking itself covers just 20 companies before the field falls off entirely — this is a landscape defined by a handful of repeat filers rather than a broad competitive set.
| Assignee | Recent year | YoY |
|---|---|---|
| ArcelorMittal | 4 | -81% |
| AUTOMATION PRESS & TOOLING AP&T AB | 0 | — |
| Outokumpu Oyj | 0 | — |
| DSM IP Assets B.V. | 0 | — |
| INNOMAQ 21 SL | 0 | — |
| Unilin BV | 0 | -100% |
| Unilin BVBA | 0 | — |
| GM Global Technology Operations LLC | 0 | — |
Where to take this analysis
The dataset points to a concentrated core and several lighter-claimed edges; the next step is testing a specific claim idea against that map.
Map a specific process step against the leader's claims
With one assignee holding 73 of 198 records, any new filing on die temperature zoning or cooling-rate control needs a claim-by-claim comparison before drafting.
Explore in EurekaCheck the coating and polymer overlaps
C09D and C08F appear in only 6.6% and 5.6% of records respectively, suggesting coated or polymer-hybrid tailored-property parts remain comparatively open.
Run a white-space searchTrack the leader's next filings
The top assignee's 81% year-on-year drop may be a publication-lag artifact rather than a real pullback; monitoring its next filings will clarify whether the window is real.
Set up monitoring in EurekaCommon questions about this landscape
In this dataset, tailored tempering and partial hardening are treated as closely related process families rather than distinct technologies: both describe creating a deliberate microstructure gradient in a single formed part, typically by controlling die temperature zoning or localized cooling rate during hot forming. Partial hardening claims tend to focus on the cooling step and mold hardware, while tailored tempering claims often extend into post-forming heat treatment. The IPC composition here shows heavy overlap between C21D heat treatment and B21D sheet-metal working, confirming the two are usually claimed together rather than separately. A freedom-to-operate search should cover both terms jointly, as this search string does.
The ranking covers 20 assignees, with the leader holding 73 of the 198 records in scope and the top 5 combined holding 159 records, or 80.3% of the field. That concentration falls off sharply after fifth place, where the total is 10 records, and by tenth place it is down to 4. The named leaders in this space are steel producers and forming-equipment specialists rather than a broad set of automakers, which matters when assessing supplier versus OEM freedom to operate.
Yes, based on the years that can be read reliably. Filings rose from 14 in 2021 to a peak of 34 in 2024, a 143% increase over that three-year span. Counts for 2025 and 2026 appear lower in the raw data, but that reflects the roughly 18-month lag between filing and publication rather than an actual slowdown, so those two years should not yet be read as a trend reversal.
US10378089B2, assigned to Thyssenkrupp Steel Europe and published in 2019, claims a method and mold device for partially hardening semifinished hardenable-steel products. The core steps are heating regions of the product above the AC1 temperature, positioning it in a mold with an active cooling element adjacent to or in contact with the heated regions, and cooling those regions at a defined rate to produce a hardened microstructure locally while leaving adjacent zones softer. Anyone using zoned active mold cooling on AC1-heated steel blanks should read this claim set closely before finalizing a process design.
The IPC composition points to two comparatively light branches: coatings (C09D, 6.6% of the 198 records) and addition polymers (C08F, 5.6%), both far behind the dominant C21D heat treatment claims at 40.9%. Furnace hardware under F27D also sits lower at 8.6%. A filing that combines a coated or polymer-hybrid blank with tailored hardening, or that focuses on furnace-side zoning hardware rather than mold-side cooling, is claiming into a less crowded part of the map, though it should still be checked against the leading assignee's 73 records.
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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.