Flatness and Profile Control Patents: Mapping the Rolling Mill Field
43.7% concentration. The top 5 assignees combined account for 289 of the 662 records in scope — the field's core flatness and shape-control claims sit with a small group. Filings peaked at 34 in 2017. The confirmed comparison point — 2021 at 10 records against 2024 at 3 — shows a 70% decline over that three-year span. 2025 and 2026 figures are not yet a reliable read on real filing activity: publication typically lags filing by around 18 months, so recent-year counts will keep rising as more records publish.
- 1NUCOR CORP73
- 2HITACHI LTD65
- 3SMS GROUP GMBH62
- 4IHI CORP49
- 5ABB AB40
See the full flatness and profile control 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
Questions practitioners ask about this field
Who holds the most patents in strip flatness and profile control?
The ranked leader in this dataset holds 73 records, well ahead of fifth place at 40 and tenth place at 22. The top 5 assignees combined account for 43.7% of all 662 records in scope, and the top 10 account for 67.2%. This is a concentrated field: a handful of rolling-mill equipment suppliers and steelmakers hold most of the core work roll bending, shifting and crown-control claims, with a long tail of single-filing entrants behind them.
Is patent filing in this area growing or declining?
Filing peaked at 34 records in 2017 and has not returned to that level since. The most recent reliable comparison, 2021 against 2024, shows a 70% decline from 10 records to 3. Figures for 2025 and 2026 are still incomplete because publication typically lags actual filing by around 18 months, so those years will rise as more records publish, but the confirmed 2021-2024 trend is a genuine slowdown, not a lag artefact.
What technology areas are covered under flatness and profile control patents?
The large majority of records, 86.6%, sit in IPC class B21B, metal rolling, covering work roll bending, shifting and crown-profile hardware. Measurement systems (G01B) appear in 10.3% of records, casting-related claims (B22D) in 5.6%, control and regulating systems (G05B) in 5.1%, and force or pressure measurement (G01L) in 4.1%. Because a record can carry multiple IPC classes, these shares add up to more than 100% and should be read individually against the 662-record total, not summed.
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 Flatness and Profile Control 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.