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 grant trajectory.

Compiled by PlainPatent · May 15, 2026

1,895
US patents granted: #2/9
in B21: 12.2%
B21 class share: -4%
5-yr velocity

The verdict

According to USPTO PatentsView, Rolling Of Metal ranks #371 of 670 CPC technology areas - 1,895 US patents granted since 2015, with recorded grant volume down 4% over five years.

#371
of 670 CPC technology areas: 1,895
US patents granted, 2015–2025: Sms group
leading assignee (145): -4%
grant velocity, last 5 yrs

How B21B's grant cadence moved

Between 2020–2024, B21B recorded 829 grants versus 867 in 2015–2019 (-4% equal-window velocity). Across complete years, output peaked in 2019 at 193 grants and bottomed in 2024 at 140 (+38% peak-over-trough). Lead assignee SMS group GmbH holds 7.7% of the class ; the top three share 19.3%.

Leaderboard read

B21B concentration, lead at 7.7%

SMS group GmbH leads this historical grant record at 7.7% of B21B - foreign corporation assignees hold 88% of class grants (1,144 of 1,294). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 7.7%
Top three share: 19.3%
Lead over #2: 35

Where B21B sits inside B21

Among 9 subclasses in B21 (Mechanical Metal-working Without Essentially Removing MATERIAL; Punching Metal), B21B ranks #2 and holds 12.2% of the parent class's 15,472 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

B21D 7,309 B21C 1,874 B21J 1,805 B21K 1,246 B21F 817 B21H 386 B21G 86 B21L 54

Rising assignees active in B21B

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 Tmeic Corporation 24x 2 → 48 company-wide · 5 in B21B
#2 Jiangsu Kangrui New Material Technology Co., Ltd. 7.00x 1 → 7 company-wide · 5 in B21B
#3 Yanshan University 4.33x 12 → 52 company-wide · 8 in B21B
#4 Taiyuan University OF Technology 2.40x 30 → 72 company-wide · 15 in B21B
#5 Hyundai Steel Company 2.08x 13 → 27 company-wide · 9 in B21B

B21B grants by year, peak 2019 (193)

US utility-patent grants per year in B21B, 2015–2025 - recent five years are down 4% versus 2015–2019.

Sms group

145
Jfe Steel

110
Nippon Steel &…

110
Nippon Steel

76
Primetals Austria

72
Danieli & C Officine…

68
Primetals Germany

49
Novelis

43
Baoshan Iron & Steel

42
Posco

41
Toshiba Mitsubishi-ele…

29
Arcelormittal

24

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.

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

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).

Classes near B21B's 1,895-grant footprint

Nationwide nearest neighbors for B21B (#371 of 670 by volume ; lead share 7.7%) - not the B21 parent-class siblings above.

Nearest by grant volume

B21C 1,874 D04B 1,864 E02B 1,837 F22B 1,959

Nearest by lead-assignee share

B60R 7.6% B60Y 7.7% H04W 7.6% B62H 7.7%

Questions about B21B

Which company holds the most patents in B21B?

SMS group GmbH leads B21B with 145 patents (7.7% of the subclass). By PatentsView assignee type, foreign corporations account for 88% of class grants.

Which B21B assignees grew fastest recently?

Among assignees with ≥5 grants in B21B, Tmeic Corporation shows the highest company-wide grant multiple (24x: 2 grants in 2019–2021 → 48 in 2022–2024) while holding 5 patents in this subclass. Growth is company-wide, not class-only.

How does B21B compare inside parent class B21?

Inside B21 (Mechanical Metal-working Without Essentially Removing MATERIAL; Punching Metal), B21B ranks #2 of 9 subclasses by grant volume and holds 12.2% of the parent class total. The largest sibling is B21D (7,309 grants).

What to do with this data

B21B in context - here's where to go next.

SMS group GmbH leads B21B with 145 grants in this class. See full portfolio
B21B ranks #371 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class B21, the largest sibling subclass is B21D with 7,309 grants. Explore B21D

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

Methodology - B21B figures are USPTO PatentsView granted-utility totals for this subclass (1,895 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.