Skin Pass and Temper Rolling Patents: Leaders & Filing Trends 2026
- Filing is heavily concentrated: the ranked leaders' top 5 assignees account for 63.7% of all 1,909 records, and the top 10 for 79.6%.
- Activity peaked in 2019 at 106 filings, then declined 75% from 69 filings in 2021 to 17 in 2024, the last complete filing year.
- Claims cluster around heat treatment and alloys, with C21D and C22C each appearing in over half of all 1,909 records, leaving equipment and coating routes thinner.
Filing growth compares 2021 (69 records) with 2024 (17) — 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 1,909 records in scope (CR5), not by the ranked leaders only.
What this patent landscape covers
This landscape covers 1,909 published patent records filed between 2015 and 2026 that address temper rolling, skin pass milling and closely related process controls — elongation control, roughness transfer, yield point elongation, roll texturing methods, coating adhesion, and strip shape correction. The scope spans both the mechanical rolling step and the compositional and heat-treatment parameters that determine its outcome, since most filings claim these together rather than in isolation.
Records were pulled from receiving offices including Japan, the European Patent Office, the United States, India, Canada and Germany, reflecting where major steel producers file first. The most recent one to two years are undercounted because publication typically lags filing by roughly 18 months, so any read of the latest filing years should treat them as a floor, not a final figure.
Filing trends and technology composition
The dataset spans 1,909 published records filed between 2015 and 2026, covering temper rolling, skin pass milling and related strip surface and coating adhesion techniques.
Filing activity peaked in 2019, then declined
Filings rose from 31 in 2017 to a peak of 106 in 2019, then fell steadily; the 2021-to-2024 span shows a 75% decline, from 69 to 17 filings. Because publication lags filing by roughly 18 months, the 2025 and 2026 figures are still incomplete and should not be read as a continued drop.
Heat treatment and alloy composition dominate the claim space
C21D (heat treatment of metals) appears in 60.9% of the 1,909 records and C22C (alloys) in 55.1%, confirming that most claimed value sits in process parameters and composition rather than mill hardware. Coating-related C23C follows at 34.5%, with rolling equipment (B21B) and electroplating (C25D) each in the 15% range.
Shares are the percentage of the 1,909 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Skin Pass and Temper Rolling with Eureka
This page is one run against one query. Ask Eureka your own question about skin pass and temper rolling and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative and most-cited filings
Steel sheet for bottom covers of aerosol cans and method for producing same
A steel sheet for bottom covers of aerosol cans defined by a tight compositional window (carbon, manganese, phosphorus, aluminium and nitrogen ranges, with silicon and sulphur capped low) combined with post-aging mechanical properties: yield point of 460 to 540 MPa, total elongation of 15% or more, and yield point elongation of 6% or less, tied to a thickness-dependent yield point formula.Filed by Nippon Steel Corporation, published 2016-04-19.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20060041448A1 | Number of new and unique manufacturing and assembley methods and processes to cost effectively refit and mark… | 146 |
| 2 | US5789066A | Method and device for manufacturing cold rolled metal sheets or strips and metal sheets or strips obtained | 112 |
| 3 | JP1989319661A | Alloying hot dip galvanized steel sheet excellent in press formability | 95 |
| 4 | US5555756A | Method of lubricating steel strip for cold rolling, particularly temper rolling | 63 |
| 5 | JP1984031827A | Production of quench hardenable steel plate for ultra deep drawing | 63 |
| 6 | US20020114884A1 | Process for applying a coating to a continuous steel sheet and a coated steel sheet product therefrom | 59 |
| 7 | WO2009095264A1 | Method of producing a hot-rolled TWIP-steel and a TWIP-steel product produced thereby | 58 |
| 8 | EP1291448A1 | Cold rolled steel sheet and galvanized steel sheet having strain aging hardening property and method for prod… | 49 |
| 9 | US6410163B1 | High strength thin steel sheet, high strength alloyed hot-dip zinc-coated steel sheet, and method for produci… | 43 |
| 10 | JP1984038337A | Manufacture of steel plate with burning hardenability for extremely deep drawing | 43 |
Citation counts favour older filings within the searched corpus and should be read as a signal of historical influence, not current commercial weight.
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Three patterns stand out once the records are grouped by technology class, filing year and assignee: a concentrated ownership structure, a claim space centred on composition rather than hardware, and a filing rate that has cooled from its 2019 peak.
Ownership is concentrated at the top
The five leading assignees in the ranked leaders together account for 63.7% of the 1,909 records in scope, rising to 79.6% across the top ten. New entrants are negotiating around a small number of established portfolios rather than a fragmented field.
Composition and heat treatment dominate over hardware
C21D and C22C each appear in more than half of all records, while rolling equipment claims under B21B sit at just 15.6%. Most of the claimed value in this field is in process parameters and alloy chemistry, not mill design.
Filing has cooled sharply since the 2019 peak
Filings rose to a peak of 106 in 2019, then fell from 69 in 2021 to 17 in 2024. Publication lag means 2025-2026 figures are still incomplete, so this should be read as the field settling around established claims rather than a live collapse.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to skin pass and temper rolling, with the prior art for and against each one.
Who is filing, and where the gaps sit
Ownership of this claim space is concentrated among a small number of integrated steelmakers, with a long tail of single- or few-filing entrants behind them. Recent-year momentum suggests even the leaders have slowed new filing on the core routes.
A single assignee holds the largest single share
The leading assignee in the ranked leaders holds 426 of the 1,909 records in scope, well ahead of the fifth-place holder at 102 and tenth place at 45. This gap suggests an early and sustained filing programme rather than a recent surge.
Depth beyond the leaders is shallow
The top ten assignees together account for 79.6% of all 1,909 records, leaving relatively little room for the remaining 90 ranked companies. Filers outside this group typically hold only a handful of records each.
Some established holders have stopped filing new records
Recent-year momentum data shows multiple long-standing assignees recording zero filings in the latest tracked year, including holders with year-over-year drops of -100% and -57%. This is consistent with a claim space where core routes are already staked out.
| Assignee | Recent year | YoY |
|---|---|---|
| JFE Steel Corporation | 3 | -57% |
| POSCO | 2 | 0% |
| Nippon Steel Corporation | 0 | — |
| Tata Steel IJmuiden BV | 0 | -100% |
| Kawasaki Steel Corporation | 0 | — |
| NIPPON STEEL & SUMITOMO METAL CORP | 0 | — |
| Nippon Kokan KK | 0 | — |
| Sumitomo Metal Industries, Ltd. | 0 | — |
Where to take this analysis
The filing and ownership patterns here point to a small number of next steps depending on whether the goal is freedom-to-operate, licensing, or new filing strategy.
Check freedom-to-operate against the top holders
With 79.6% of the 1,909 records held by ten assignees, a targeted clearance search against those portfolios will cover most of the risk before a broader search is needed.
Run a clearance search in EurekaTest claim language in the under-claimed branches
Laminate adhesion, welding-integrated texturing and electron-tube-adjacent coatings show materially lower filing density than the core heat-treatment classes and are worth drafting against directly.
Draft against white space in EurekaTrack momentum, not just historical volume
Several long-standing leaders show zero filings in the latest tracked year; watching who is still actively filing matters more than who holds the largest historical stack.
Monitor assignee activity in EurekaFrequently asked questions
Temper rolling, also called skin pass rolling, applies a light final reduction to cold-rolled steel strip after annealing to suppress yield point elongation, set surface roughness, and correct strip shape. It is a finishing step rather than a primary reduction process, typically applying only a few percent of elongation. The patent evidence in this dataset shows it is most heavily claimed alongside heat treatment (C21D) and alloy composition (C22C) parameters, meaning most patents describe temper rolling as part of a broader compositional or thermal process rather than as a standalone mechanical step.
Filing is concentrated among a small group of steelmakers: the top five assignees in the ranked leaders account for 63.7% of the 1,909 records in scope, and the top ten account for 79.6%. This is a highly concentrated field compared to many process technologies, meaning a new entrant should expect to negotiate around a handful of established portfolios rather than a fragmented landscape. Recent-year momentum data shows several of these long-standing leaders filing nothing in the latest year, which points to a settled rather than actively expanding claim position for the largest holders.
Filings peaked at 106 in 2019 and fell to 17 by 2024, a decline the evidence confirms as a 75% drop between 2021 and 2024. This pattern is consistent with a claim space where the core process and composition parameters have already been staked out by the leading assignees, reducing the incentive for further filing on the same routes. It does not necessarily mean the underlying technology is obsolete — high filing density earlier in the period means available claim space is occupied, which naturally slows the rate of new filing once the major variations are covered.
Roughness transfer claims describe how a textured work roll imprints a specific surface pattern onto the strip during skin pass rolling, which is typically classified under B21B (metal rolling) alongside C23C where the resulting texture affects later coating. Coating adhesion claims instead focus on the chemical or mechanical bond between the textured surface and an applied coating layer, more often classified under C23C or C25D. In this dataset, C23C appears in 34.5% of the 1,909 records, meaning coating-related claims are a substantial secondary route behind the dominant heat treatment and alloy composition classes.
The thinnest-claimed branches in this dataset are applications adjacent to electron and discharge tubes (H01J, 2.5% of records) and welding, soldering or brazing integration (B23K, 2.0%), both far below the 60.9% share held by core heat treatment claims. Laminate and layered-product applications (B32B, 9.9%) are also comparatively open. A first filing in these areas would need to combine a specific roll-texturing or composition parameter with the adjacent application, rather than claiming surface texturing or elongation control in isolation, since those foundational elements are already densely claimed by the leading assignees.
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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.