CPC technology class · C23

C23G — Cleaning OR De-greasing OF Metallic Material BY Chemical…

Cleaning or de-greasing of metallic material by chemical methods other than electrolysis. 703 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

703
US patents granted
C23
Parent CPC class
20
Active assignees
+46%
5-yr velocity
Top assignee: NIPPON STEEL CORPORATION (41 patents)

CPC subclass C23G — CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS — covers 703 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records. This subclass sits within the broader CPC class C23 (COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTAT), one of roughly 250 top-level technology categories in the Cooperative Patent Classification system jointly maintained by the USPTO and the European Patent Office. At the subclass level, four-character codes like C23G give the most practical resolution for tracking a specific technology domain without losing sight of adjacent filings. Every grant here has been classified by a USPTO examiner based on the technical disclosure in the patent specification.

The competitive landscape in C23G is shaped by 20 distinct companies actively filing in this space. NIPPON STEEL CORPORATION leads with 41 patents, followed by JFE Steel Corporation at 1,443 grants and POSCO CO., LTD at 691. Concentration at the top of the leaderboard indicates whether this technology area is dominated by a handful of incumbents or fragmented across many filers — a useful signal for investors evaluating competitive moats and for product teams mapping freedom-to-operate risk.

Filing trajectory matters as much as static counts. The yearly series on this page plots grants from 2015 through 2025, highlighting whether innovation in C23G is accelerating, plateauing, or cooling. Technology areas with rising post-2020 activity often reflect emerging markets or new platform shifts, while declining filings can signal mature domains where incremental improvement has slowed. Researchers, licensing professionals, and competitive-intelligence teams use these patterns — together with the top-assignee distribution — to decide where to invest, where to license, and where to avoid entanglement. All counts on this page come directly from USPTO PatentsView and reflect US granted utility patents only.

Is C23G innovation accelerating?

US utility-patent grants per year in C23G, 2015–2025 — recent five years are up 46% versus 2015–2019.

30405060708090 20152016201720182019202020212022202320242025 61

Who leads C23G?

The 12 most active assignees in CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS — wider bars mean more grants

patents

What this shows Nippon Steel is the most active filer in C23G, holding 41 of the 703 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

Source USPTO PatentsView — granted utility patents As of 2015–2025 grant years
View data table

About This Class

CPC subclass C23G belongs to class C23.

703 patents were granted in this class between 2015 and 2025.

20 companies actively patent in this space.

Classification System

Cooperative Patent Classification (CPC) is a hierarchical patent classification system used by the USPTO and EPO.

Frequently Asked Questions

What is CPC class C23G?
CPC subclass C23G covers CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS. It belongs to CPC class C23 (COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTAT). The Cooperative Patent Classification is a hierarchical system used by the USPTO and European Patent Office to categorize patents by technology.
How many patents have been filed in C23G?
703 US utility patents were granted in CPC subclass C23G between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in C23G?
NIPPON STEEL CORPORATION leads C23G with 41 patents, making it the most active assignee in this technology area.
How is patent data for C23G collected?
Patent data comes from USPTO PatentsView, a public research dataset maintained by the United States Patent and Trademark Office. It covers all US granted utility patents and assigns CPC codes based on the technology described in each patent.
What is the difference between CPC class and subclass?
A CPC class (e.g., C23) is a broad technology category. Subclasses like C23G provide finer granularity within that category. PlainPatent organizes data at the subclass level (4-character codes) for the most useful view of technology domains.

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Explore the patent dataset

Data sourced from USPTO PatentsView — official U.S. government patent data. See our methodology for computation details. Retrieved and formatted by PlainPatent Editorial