PlainPatent

CPC technology class · B21

B21B - Rolling OF Metal

Rolling of metal. 1,895 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

1,895
US patents granted
B21
Parent CPC class
20
Active assignees
+9%
5-yr velocity

The verdict

Rolling OF Metal ranks #371 of 670 CPC technology areas - 1,895 US patents granted since 2015, with filing up 9% over five years.

#371
of 670 CPC technology areas
1,895
US patents granted, 2015–2025
Sms group
leading assignee (145)
+9%
filing velocity, last 5 yrs
Top assignee: SMS Group Gmbh (145 patents)

CPC subclass B21B - ROLLING OF METAL - covers 1,895 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class B21 (MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL). See our CPC classification guide for how the system works.

The competitive landscape in B21B is shaped by 20 distinct companies actively filing in this space. SMS Group Gmbh leads with 145 patents, followed by JFE Steel Corporation at 110 grants and Nippon Steel & Sumitomo Metal Corporation at 110.

Filing activity in B21B is up 9% 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 B21B innovation accelerating?

US utility-patent grants per year in B21B, 2015–2025 - recent five years are up 9% versus 2015–2019.

100120140160180200 20152016201720182019202020212022202320242025 117

Who leads B21B?

The 12 most active assignees in ROLLING OF METAL - wider bars mean more grants

patents

What this shows Sms group is the most active filer in B21B, holding 145 of the 1,895 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 B21B
Rank Company Patents in B21B
#1 SMS Group Gmbh 145
#2 JFE Steel Corporation 110
#3 Nippon Steel & Sumitomo Metal Corporation 110
#4 Nippon Steel Corporation 76
#5 Primetals Technologies Austria Gmbh 72
#6 Danieli & C. Officine Meccaniche S.p.a. 68
#7 Primetals Technologies Germany Gmbh 49
#8 Novelis Inc. 43
#9 Baoshan IRON & Steel Co., Ltd. 42
#10 Posco Co., Ltd 41
#11 Toshiba Mitsubishi-electric Industrial Systems Corporation 29
#12 Arcelormittal 24
#13 Primetals Technologies Japan, Ltd. 21
#14 UACJ Corporation 19
#15 Thyssenkrupp Steel Europe Ag 17
#16 Sandvik Materials Technology Deutschland Gmbh 17
#17 Taiyuan University OF Technology 15
#18 Primetals Technologies USA Llc 13
#19 Fives DMS 13
#20 The Bradbury Co., Inc. 11

About This Class

CPC subclass B21B belongs to class B21.

1,895 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 B21B 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 B21B assignees by class footprint. Bubble size = patents in B21B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 B21B assignees by class footprint. Bubble size = patents in B21B. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 5101520 050100150200 Patents in B21B Avg claims / patent (company-wide) Sms groupJfe SteelNippon Steel & Sumito…Nippon SteelPrimetals AustriaDanieli & C Officine…Primetals GermanyNovelisBaoshan Iron & SteelPoscoToshiba Mitsubishi-el…ArcelormittalPrimetals JapanUacj
Top 14 B21B assignees by class footprint. Bubble size = patents in B21B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class B21B?
CPC subclass B21B covers ROLLING OF METAL. It belongs to CPC class B21 (MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL), with 1,895 US utility patents granted since 2015.
How many patents have been filed in B21B?
1,895 US utility patents were granted in CPC subclass B21B between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in B21B?
SMS Group Gmbh leads B21B with 145 patents, making it the most active assignee in this technology area.
How is patent data for B21B 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., B21) is a broad technology category. Subclasses like B21B 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.