PlainPatent

CPC technology class · F27

F27D - Details OR Accessories OF Furnaces

Details or accessories of furnaces, kilns, ovens or retorts, in so far as they are of kinds occurring in more than one kind of furnace. 2,695 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

2,695
US patents granted
F27
Parent CPC class
20
Active assignees
-4%
5-yr velocity

The verdict

Details OR Accessories OF Furnaces ranks #337 of 670 CPC technology areas - 2,695 US patents granted since 2015, with filing down 4% over five years.

#337
of 670 CPC technology areas
2,695
US patents granted, 2015–2025
Molten Metal Equipmen…
leading assignee (58)
-4%
filing velocity, last 5 yrs
Top assignee: Molten Metal Equipment Innovations, Llc (58 patents)

CPC subclass F27D - DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE - covers 2,695 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class F27 (FURNACES; KILNS; OVENS; RETORTS). See our CPC classification guide for how the system works.

The competitive landscape in F27D is shaped by 20 distinct companies actively filing in this space. Molten Metal Equipment Innovations, Llc leads with 58 patents, followed by JFE Steel Corporation at 53 grants and PAUL Wurth S.a. at 47.

Filing activity in F27D is down 4% over the past five years versus 2015-2019, a relatively steady filing pace. All counts come directly from USPTO PatentsView and reflect US granted utility patents only.

Is F27D innovation accelerating?

US utility-patent grants per year in F27D, 2015–2025 - recent five years are down 4% versus 2015–2019.

150200250300 20152016201720182019202020212022202320242025 166

Who leads F27D?

The 12 most active assignees in DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE - wider bars mean more grants

patents

What this shows Molten Metal Equipmen… is the most active filer in F27D, holding 58 of the 2,695 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 F27D
Rank Company Patents in F27D
#1 Molten Metal Equipment Innovations, Llc 58
#2 JFE Steel Corporation 53
#3 PAUL Wurth S.a. 47
#4 Novelis Inc. 34
#5 Danieli & C. Officine Meccaniche S.p.a. 31
#6 Outotec (finland) OY 30
#7 Primetals Technologies Austria Gmbh 28
#8 Ivoclar Vivadent Ag 23
#9 Refractory Intellectual Property Gmbh & Co. KG 23
#10 ASM IP Holding B.v. 22
#11 AIR Products AND Chemicals, Inc. 21
#12 Pyrotek, Inc. 20
#13 Outotec Oyj 18
#14 Posco Co., Ltd 16
#15 SMS Group Gmbh 16
#16 Saint-gobain Centre DE Recherches ET D'etudes Europeen 16
#17 Hatch Ltd. 16
#18 Systems Spray-cooled, Inc. 16
#19 Suncoke Technology AND Development Llc 14
#20 Inductotherm Corp. 14

About This Class

CPC subclass F27D belongs to class F27.

2,695 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.

← All Technology Classes Technology Rankings →

Footprint here vs. claim strategy

Each dot is a leading F27D 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 F27D assignees by class footprint. Bubble size = patents in F27D. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 F27D assignees by class footprint. Bubble size = patents in F27D. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 510152025 10203040506070 Patents in F27D Avg claims / patent (company-wide) Molten Metal Equipmen…Jfe SteelPaul WurthNovelisDanieli & C Officine…Outotec (Finland) OyPrimetals AustriaIvoclar VivadentRefractory Intellectu…Asm Ip Holding B VAir Products And Chem…PyrotekOutotec OyjPosco
Top 14 F27D assignees by class footprint. Bubble size = patents in F27D. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class F27D?
CPC subclass F27D covers DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE. It belongs to CPC class F27 (FURNACES; KILNS; OVENS; RETORTS), with 2,695 US utility patents granted since 2015.
How many patents have been filed in F27D?
2,695 US utility patents were granted in CPC subclass F27D between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in F27D?
Molten Metal Equipment Innovations, Llc leads F27D with 58 patents, making it the most active assignee in this technology area.
How is patent data for F27D 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., F27) is a broad technology category. Subclasses like F27D provide finer granularity within that category. PlainPatent organizes data at the subclass level (4-character codes) for the most useful view of technology domains.

Read our methodology - how this data is sourced, computed, and verified.

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

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.