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 grant trajectory.

Compiled by PlainPatent · May 15, 2026

703
US patents granted: #3/4
in C23: 2.1%
C23 class share: +23%
5-yr velocity

The verdict

According to USPTO PatentsView, Cleaning Or De-greasing Of Metallic Material By Chemical… ranks #500 of 670 CPC technology areas - 703 US patents granted since 2015, with recorded grant volume up 23% over five years.

#500
of 670 CPC technology areas: 703
US patents granted, 2015–2025: Nippon Steel
leading assignee (41): +23%
grant velocity, last 5 yrs

How C23G's grant cadence moved

Between 2020–2024, C23G recorded 333 grants versus 270 in 2015–2019 (+23% equal-window velocity). Across complete years, output peaked in 2022 at 79 grants and bottomed in 2018 at 40 (+98% peak-over-trough). Lead assignee Nippon Steel Corporation holds 5.8% of the class ; the top three share 13.8%.

Leaderboard read

C23G concentration, lead at 5.8%

Nippon Steel Corporation leads this historical grant record at 5.8% of C23G - foreign corporation assignees hold 84% of class grants (228 of 270). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 5.8%
Top three share: 13.8%
Lead over #2: 2

Where C23G sits inside C23

Among 4 subclasses in 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), C23G ranks #3 and holds 2.1% of the parent class's 33,270 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

C23C 29,488 C23F 2,985 C23D 94

Rising assignees active in C23G

Company-wide grant multiples (2022–2024 vs 2019–2021) among assignees with ≥5 patents in this subclass. Growth is company-wide; class patent counts are subclass-specific.

#1 Dorf Ketal Chemicals FZE 12x 2 → 24 company-wide · 6 in C23G
#2 Nippon Steel Stainless Steel Corporation 4.75x 4 → 19 company-wide · 5 in C23G
#3 Hyundai Steel Company 2.08x 13 → 27 company-wide · 6 in C23G
#4 Posco Co., Ltd 1.62x 170 → 275 company-wide · 17 in C23G
#5 Fluid Energy Group Ltd. 1.58x 12 → 19 company-wide · 9 in C23G

C23G grants by year, peak 2022 (79)

US utility-patent grants per year in C23G, 2015–2025 - recent five years are up 23% versus 2015–2019.

Nippon Steel

41
Jfe Steel

39
Posco

17
Arcelormittal

11
Fujifilm Materials U

10
Fluid Energy Group

9
Chemetall

8
Primetals Japan

7
Biomet 3i

6
Toyo Kohan

6
Hyundai Steel

6
Dorf Ketal Chemicals…

6

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.

View data table

Top patent holders in CPC subclass C23G
Rank	Company	Patents in C23G
#1	Nippon Steel Corporation	41
#2	JFE Steel Corporation	39
#3	Posco Co., Ltd	17
#4	ArcelorMittal	11
#5	Fujifilm Electronic Materials U.S.A., Inc.	10
#6	Fluid Energy Group Ltd.	9
#7	Chemetall GMBH	8
#8	Primetals Technologies Japan, Ltd.	7
#9	Biomet 3i, LLC	6
#10	Toyo Kohan Co., Ltd.	6
#11	Hyundai Steel Company	6
#12	Dorf Ketal Chemicals FZE	6
#13	Nippon Steel Stainless Steel Corporation	5
#14	Organo Corporation	4
#15	Advanced Technology & Materials Co., Ltd.	4
#16	IHI Machinery AND Furnace Co., Ltd.	4
#17	Green Products & Technologies, LLC	4
#18	Houghton Technical Corp.	4
#19	Prc-desoto International, Inc.	3
#20	Hydro Aluminum Rolled Products GmbH	3

Footprint here vs. claim strategy

Each dot is a leading C23G assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 C23G assignees by class footprint. Bubble size = patents in C23G. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near C23G's 703-grant footprint

Nationwide nearest neighbors for C23G (#500 of 670 by volume ; lead share 5.8%) - not the C23 parent-class siblings above.

Nearest by grant volume

A24C 702 C25F 701 C05D 707 B09C 712

Nearest by lead-assignee share

C07J 5.8% B07B 5.9% B31B 5.9% B03D 5.9%

Questions about C23G

Which company holds the most patents in C23G?

Nippon Steel Corporation leads C23G with 41 patents (5.8% of the subclass). By PatentsView assignee type, foreign corporations account for 84% of class grants.

Which C23G assignees grew fastest recently?

Among assignees with ≥5 grants in C23G, Dorf Ketal Chemicals FZE shows the highest company-wide grant multiple (12x: 2 grants in 2019–2021 → 24 in 2022–2024) while holding 6 patents in this subclass. Growth is company-wide, not class-only.

How does C23G compare inside parent class C23?

Inside 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), C23G ranks #3 of 4 subclasses by grant volume and holds 2.1% of the parent class total. The largest sibling is C23C (29,488 grants).

What to do with this data

C23G in context - here's where to go next.

Nippon Steel Corporation leads C23G with 41 grants in this class. See full portfolio
C23G ranks #500 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class C23, the largest sibling subclass is C23C with 29,488 grants. Explore C23C

Figures reflect USPTO PatentsView grant data through 2026-05-15; pending applications not yet granted are not counted.

Methodology - C23G figures are USPTO PatentsView granted-utility totals for this subclass (703 grants in the tracked window).

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.