Heavy Ingot Casting Patents: Top Companies & Filing Trends 2026
- Filing peaked in 2021 at 9 records, then fell 78% to 2 by 2024 — a field that saw a short burst of activity rather than sustained build-out.
- The top 5 assignees hold 45.0% of all 60 records in scope — concentrated enough that a new entrant needs to check freedom-to-operate against a small set of holders before filing.
- B22D metal casting covers 78.3% of records — nearly every filing touches casting mechanics, while heat treatment and alloy composition claims are comparatively thin.
Filing growth compares 2021 (9 records) with 2024 (2) — 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 60 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Heavy ingot casting and segregation covers the mechanics of pouring, solidifying and controlling composition in large metal ingots: hot top casting, mould taper, pouring temperature, insulating powder practice and the channel segregation and shrinkage cavity defects that these process choices are meant to prevent. The 60 records in scope span 2015 through the 2026 cutoff and draw on filing activity from steelmakers, aluminium producers and foundry equipment suppliers rather than a single dominant industry segment.
Because publication lags filing by roughly 18 months, the last one to two years in any trend chart will understate true filing activity — treat 2024 as the most recent year with a reasonably complete picture.
Filing trend and technology composition
Two views of the same 60-record dataset: how filing activity has moved year over year, and which IPC subclasses the claims actually sit in.
Filing rose and fell in a single cycle
Filing climbed to a peak of 9 records in 2021, then declined to 2 by 2024 — a 78% drop over that three-year span. Earlier years, including 2017, show no filings at all, so the entire visible cycle in this dataset plays out inside a roughly seven-year window.
Casting mechanics dominate the class mix
B22D (metal casting) appears in 78.3% of all 60 records, far ahead of any other subclass. C22C (alloys) and C21D (heat treatment) each cover a meaningful minority of filings, while B22C (foundry moulding), C04B (refractories), C21C (steelmaking), C22B (metal refining) and B21B (rolling) each appear in single-digit percentages — these are the narrower, less-contested branches of the same problem space.
Shares are the percentage of the 60 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Heavy Ingot Casting and Segregation with Eureka
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Try EurekaA representative early claim
Apparatus for pouring hot top ingots by weight
Ingot yield is improved by changing teeming practice to pouring ingot body and hot top by weight rather than by volume to a mark on a hot top casting. Correct weight addition to the ingot hot top is calculated by a computerized weight-loss weigher system using either a value related to ingot mold body size or a percentage of body weight. Calculation is initiated either manually or automatically when hot metal level is detected at the bottom of the hot top casting.Filed by Bethlehem Steel Corp — an early example of instrumented, weight-based pouring control rather than volume-based teeming.
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Three read-outs from the same dataset: how concentrated ownership is, where the technical weight of filings sits, and where activity is heading.
Ownership sits with a small group
The top 5 assignees account for 45.0% of all 60 records in scope, and the top 10 extend that to 61.7%. The leader alone holds 10 records against a fifth-place count of 2 — a steep drop-off that marks a genuine leader-plus-long-tail structure rather than a crowded middle.
Casting process, not alloy chemistry, is where claims sit
Metal casting mechanics (B22D) touch the large majority of filings, while alloy composition (C22C) and heat treatment (C21D) cover smaller, overlapping subsets. Foundry moulding, refractories, steelmaking and rolling each appear in only a handful of records, suggesting the field is defined more by pouring and solidification control than by material formulation.
A short filing cycle, now past its peak
Filing activity rose to 9 records in 2021 and had fallen to 2 by 2024, a 78% decline over that span. None of the named leading assignees show filings in the latest tracked year, consistent with a technology area that saw a defined burst of activity rather than continuous investment.
Filing is spread across a handful of major offices
The United States leads with 17 filings, followed by Japan at 13; Australia, China, the EPO and the United Kingdom each account for single-digit counts. That spread points to a technology prosecuted mainly through established steel- and aluminium-producing jurisdictions rather than concentrated in one region.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to heavy ingot casting and segregation, with the prior art for and against each one.
Who holds the claims, and where the gaps are
A leader with a clear filing lead, a long tail of single- or double-filing entrants, and a handful of adjacent branches that none of them have claimed heavily.
One assignee holds a clear lead
The top-ranked assignee holds 10 records, well ahead of the fifth-place holder's 2 — a gap wide enough that its portfolio is the first stop for freedom-to-operate checks in hot top and weight-based pouring control.
Most of the ranked list files rarely
By the tenth position, holdings drop to 2 records, and the ranking includes 31 companies overall — most of them likely holding only one or two filings each. That structure favours a targeted licensing or design-around strategy over a blanket clearance search.
Joint filing is rare but not absent
Only two co-assignee pairs appear in the dataset, the strongest linking two Furukawa aluminium entities across three shared records. This is a field of largely independent filers rather than joint-venture-driven patenting.
| Assignee | Recent year | YoY |
|---|---|---|
| Wagstaff Inc | 0 | — |
| Jiangyin Xingcheng Special Steel Works Co Ltd | 0 | — |
| Pechiney Rhenalu | 0 | — |
| Kawasaki Steel Corp | 0 | — |
| FURUKAWA ARUMINIUMU KOUGIYOU KK | 0 | — |
| FURUKAWA ALUMINUM CO LTD | 0 | — |
| Resonac Holdings Corporation | 0 | — |
| Bethlehem Steel Corp | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is clearance, licensing or new filing strategy.
Run a freedom-to-operate check against the leader
With one assignee holding 10 of 60 records, any new hot top or weight-based pouring system should be checked against that portfolio before development spend goes further.
Explore assignee portfolios in EurekaTest the under-claimed branches
Insulating powder formulation, mould taper design and refractory composition each carry only a few records — a first claim drafted carefully in one of these areas may face a thinner prior-art field than the crowded casting-mechanics core.
Map white space in EurekaWatch for the next filing cycle
The 2021 peak and subsequent decline suggest this technology moves in bursts tied to capital cycles in steel and aluminium production; a renewed uptick in raw material or energy costs could trigger the next wave.
Track filing trends in EurekaCommon questions on this landscape
The ranked list covers 31 companies, with the leading assignee holding 10 of the 60 records in scope and the top 5 combined accounting for 45.0% of all records. Holdings drop sharply after the leader, with the fifth-ranked and tenth-ranked assignees each holding only 2 records. This means the field has one clear leader plus a long tail of firms with one or two filings each, so a competitive review should start with the leader's portfolio rather than treating the field as evenly contested.
No — filing peaked at 9 records in 2021 and had fallen to 2 by 2024, a 78% decline over that span. Because publication lags filing by roughly 18 months, 2025 and later data is still incomplete, but the 2021-to-2024 trend already shows a clear pullback from peak activity. Anyone assessing this space should treat it as past a filing burst rather than in an active growth phase.
The large majority, 78.3% of all 60 records, sit in IPC subclass B22D covering metal casting mechanics such as pouring and mould control. Alloy composition (C22C) and heat treatment (C21D) each cover smaller but notable shares, while foundry moulding, refractories, steelmaking, metal refining and rolling each appear in only a handful of records. This tells a practitioner that most competitive activity is about how the metal is poured and solidified, not what alloy it is made from.
Sub-areas like insulating powder formulation, mould taper optimisation for large-section ingots, refractory composition for solidification control and pouring temperature feedback systems each carry only a small number of records relative to the core casting-mechanics claims. These branches sit inside the same overall problem space but have not attracted the same density of filing, which makes them worth a closer novelty search before assuming a first claim there would face heavy prior art. High density elsewhere in the field means claim space is occupied there, not that these adjacent branches are automatically clear too.
The United States leads with 17 filings, followed by Japan at 13, with Australia, China, the European Patent Office and the United Kingdom each in single digits. This spread reflects filing through the major steel- and aluminium-producing jurisdictions rather than concentration in any single region, and it should inform where a competitor clearance search or licensing outreach is prioritised.
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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.