PlainPatent

CPC technology class · C23

C23D - Enamelling Of

Enamelling of, or applying a vitreous layer to, metals. 94 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

94
US patents granted
#4/4
in C23
0.3%
C23 class share
+72%
5-yr velocity

The verdict

According to USPTO PatentsView, Enamelling Of ranks #622 of 670 CPC technology areas - 94 US patents granted since 2015, with recorded grant volume up 72% over five years.

#622
of 670 CPC technology areas
94
US patents granted, 2015–2025
Lg
leading assignee (9)
+72%
grant velocity, last 5 yrs

How C23D's grant cadence moved

Between 2020–2024, C23D recorded 50 grants versus 29 in 2015–2019 (+72% equal-window velocity). Across complete years, output peaked in 2021 at 14 grants and bottomed in 2016 at 3 (+367% peak-over-trough). Lead assignee Suncoke Technology AND Development LLC holds 6.4% of the class ; the top three share 11.7%.

Leaderboard read

C23D concentration, lead at 6.4%

Suncoke Technology AND Development LLC leads this historical grant record at 6.4% of C23D - us corporation assignees hold 59% of class grants (10 of 17). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share
6.4%

6 of 94 grants

Top three share
11.7%

of the class's recorded grants

Lead over #2
3

more grants than ZYP Coatings, Inc.

Where C23D 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), C23D ranks #4 and holds 0.3% 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 C23G 703

Rising assignees active in C23D

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. #1 Suncoke Technology AND Development LLC 1.03x 29 → 30 company-wide · 6 in C23D

C23D grants by year, peak 2021 (14)

US utility-patent grants per year in C23D, 2015–2025 - recent five years are up 72% versus 2015–2019.

051015 20152016201720182019202020212022202320242025 11

Who leads C23D?

The 12 most active assignees in Enamelling OF, OR Applying A Vitreous Layer TO, Metals - wider bars mean more grants

patents

What this shows Lg is the most active filer in C23D, holding 9 of the 94 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
Top patent holders in CPC subclass C23D
Rank Company Patents in C23D
#1 Suncoke Technology AND Development LLC 6
#2 ZYP Coatings, Inc. 3
#3 EPG (ENGINEERED Nanoproducts GERMANY) AG 2
#4 BHI Co., Ltd. 2
#5 Nihon Parkerizing Co., Ltd. 1
#6 MiiR Holdings, LLC 1
#7 MICLAU-S.R.I. Inc. 1
#8 Ehime Prefecture 1

Footprint here vs. claim strategy

Each dot is a leading C23D 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 8 C23D assignees by class footprint. Bubble size = patents in C23D. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 8 data points (bubble-sized by third dimension). 05101520 02468 Patents in C23D Avg claims / patent (company-wide) Suncoke Technology…Zyp CoatingsEpg (Engineered…BhiNihon ParkerizingMiir HoldingsMiclau-s R IEhime Prefecture
Top 8 C23D assignees by class footprint. Bubble size = patents in C23D. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Questions about C23D

Which company holds the most patents in C23D?
LG Electronics Inc. leads C23D with 9 patents (6.4% of the subclass). By PatentsView assignee type, us corporations account for 59% of class grants.
Which C23D assignees grew fastest recently?
Among assignees with ≥5 grants in C23D, Suncoke Technology AND Development LLC shows the highest company-wide grant multiple (1.03x: 29 grants in 2019–2021 → 30 in 2022–2024) while holding 6 patents in this subclass. Growth is company-wide, not class-only.
How does C23D 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), C23D ranks #4 of 4 subclasses by grant volume and holds 0.3% of the parent class total. The largest sibling is C23C (29,488 grants).

What to do with this data

C23D in context - here's where to go next.

  • Suncoke Technology AND Development LLC leads C23D with 6 grants in this class. See full portfolio
  • C23D ranks #622 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 - C23D figures are USPTO PatentsView granted-utility totals for this subclass (94 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.