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CPC technology class · B21

B21L - Making Metal Chains

Making metal chains. 54 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

54
US patents granted
#9/9
in B21
0.3%
B21 class share
-4%
5-yr velocity

The verdict

According to USPTO PatentsView, Making Metal Chains ranks #639 of 670 CPC technology areas - 54 US patents granted since 2015, with recorded grant volume down 4% over five years.

#639
of 670 CPC technology areas
54
US patents granted, 2015–2025
Schaeffler & Kg
leading assignee (3)
-4%
grant velocity, last 5 yrs

How B21L's grant cadence moved

Between 2020–2024, B21L recorded 23 grants versus 24 in 2015–2019 (-4% equal-window velocity). Across complete years, output peaked in 2016 at 7 grants and bottomed in 2017 at 3 (+133% peak-over-trough). Lead assignee Iwis Motorsysteme GMBH & Co. KG holds 5.6% of the class ; the top three share 13.0%.

Leaderboard read

B21L concentration, lead at 5.6%

Iwis Motorsysteme GMBH & Co. KG leads this historical grant record at 5.6% of B21L - us corporation assignees hold 52% of class grants (11 of 21). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share
5.6%

3 of 54 grants

Top three share
13.0%

of the class's recorded grants

Lead over #2
1

more grants than Blount, Inc.

Where B21L sits inside B21

Among 9 subclasses in B21 (Mechanical Metal-working Without Essentially Removing MATERIAL; Punching Metal), B21L ranks #9 and holds 0.3% 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 B21B 1,895 B21C 1,874 B21J 1,805 B21K 1,246 B21F 817 B21H 386 B21G 86

B21L grants by year, peak 2016 (7)

US utility-patent grants per year in B21L, 2015–2025 - recent five years are down 4% versus 2015–2019.

2345678 20152016201720182019202020212022202320242025 5

Who leads B21L?

The 12 most active assignees in Making Metal Chains - wider bars mean more grants

patents

What this shows Schaeffler & Kg is the most active filer in B21L, holding 3 of the 54 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 B21L
Rank Company Patents in B21L
#1 Iwis Motorsysteme GMBH & Co. KG 3
#2 Blount, Inc. 2
#3 Wolf Tooth Components, LLC 2
#4 FMH Conveyors LLC 2
#5 Rexnord Flattop Europe B.V. 1
#6 Central Iron AND Steel Research Institute 1
#7 Rexnord Industries, LLC 1
#8 Daido Kogyo Co., Ltd. 1
#9 Crossfor Co., Ltd. 1
#10 Poul Chang Metal Industry Co., Ltd. 1
#11 Marco Bicego S.P.A. 1
#12 Samson Rope Technologies, Inc. 1
#13 One Pass Innovators, LLC 1
#14 Cosberg S.P.A. 1
#15 Picote Solutions Inc. 1
#16 David Yurman IP LLC 1

Footprint here vs. claim strategy

Each dot is a leading B21L 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 B21L assignees by class footprint. Bubble size = patents in B21L. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 0510152025 0.511.522.533.5 Patents in B21L Avg claims / patent (company-wide) Iwis Motorsysteme & KgBlountWolf Tooth ComponentsFmh ConveyorsRexnord Flattop…Central Iron And…Rexnord IndustriesDaido KogyoCrossforPoul Chang Metal…Marco Bicego S P ASamson RopeOne Pass InnovatorsCosberg S P A
Top 14 B21L assignees by class footprint. Bubble size = patents in B21L. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Questions about B21L

Which company holds the most patents in B21L?
Schaeffler Technologies AG & Co. KG leads B21L with 3 patents (5.6% of the subclass). By PatentsView assignee type, us corporations account for 52% of class grants.
How does B21L compare inside parent class B21?
Inside B21 (Mechanical Metal-working Without Essentially Removing MATERIAL; Punching Metal), B21L ranks #9 of 9 subclasses by grant volume and holds 0.3% of the parent class total. The largest sibling is B21D (7,309 grants).

What to do with this data

B21L in context - here's where to go next.

  • Iwis Motorsysteme GMBH & Co. KG leads B21L with 3 grants in this class. See full portfolio
  • B21L ranks #639 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 - B21L figures are USPTO PatentsView granted-utility totals for this subclass (54 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.