CPC technology class · B23

B23C - Milling

Milling. 2,322 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

2,322
US patents granted: #6/9
in B23: 4.9%
B23 class share: -22%
5-yr velocity

The verdict

According to USPTO PatentsView, Milling ranks #353 of 670 CPC technology areas - 2,322 US patents granted since 2015, with recorded grant volume down 22% over five years.

#353
of 670 CPC technology areas: 2,322
US patents granted, 2015–2025: Kennametal
leading assignee (158): -22%
grant velocity, last 5 yrs

How B23C's grant cadence moved

Between 2020–2024, B23C recorded 926 grants versus 1,185 in 2015–2019 (-22% equal-window velocity). Across complete years, output peaked in 2018 at 289 grants and bottomed in 2024 at 138 (+109% peak-over-trough). Lead assignee Kennametal Inc. holds 6.8% of the class ; the top three share 16.5%.

Leaderboard read

B23C concentration, lead at 6.8%

Kennametal Inc. leads this historical grant record at 6.8% of B23C - foreign corporation assignees hold 74% of class grants (1,107 of 1,502). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 6.8%
Top three share: 16.5%
Lead over #2: 40

Where B23C sits inside B23

Among 9 subclasses in B23 (Machine TOOLS; Metal-working NOT Otherwise Provided FOR), B23C ranks #6 and holds 4.9% of the parent class's 47,646 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

B23K 21,060 B23P 8,569 B23Q 5,906 B23B 5,282 B23D 2,856 B23H 839 B23F 529 B23G 283

Rising assignees active in B23C

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 AB Sandvik Coromant 17x 0 → 17 company-wide · 5 in B23C
#2 Qingdao University OF Technology 4.22x 23 → 97 company-wide · 8 in B23C
#3 Shenzhen Xhorse Electronics Co., Ltd 3.00x 2 → 6 company-wide · 7 in B23C
#4 Kennametal India Ltd. 3.00x 2 → 6 company-wide · 5 in B23C
#5 Kyocera SGS Precision Tools, Inc. 2.50x 2 → 5 company-wide · 7 in B23C

B23C grants by year, peak 2018 (289)

US utility-patent grants per year in B23C, 2015–2025 - recent five years are down 22% versus 2015–2019.

Kennametal

158
Kyocera

118
Tungaloy

106
Sumitomo Electric…

101
Iscar

92
Sandvik Intellectual…

81
Mitsubishi Materials

50
The Hillman Group

42
Seco Tools Ab

42
Korloy

26
Makino Milling Machine

21
Franz Haimer…

21

What this shows Kennametal is the most active filer in B23C, holding 158 of the 2,322 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 B23C
Rank	Company	Patents in B23C
#1	Kennametal Inc.	158
#2	Kyocera Corporation	118
#3	Tungaloy Corporation	106
#4	Sumitomo Electric Hardmetal Corp.	101
#5	Iscar, Ltd.	92
#6	Sandvik Intellectual Property AB	81
#7	Mitsubishi Materials Corporation	50
#8	THE Hillman Group, Inc.	42
#9	Seco Tools AB	42
#10	Korloy Inc.	26
#11	Makino Milling Machine Co., Ltd.	21
#12	Franz Haimer Maschinenbau KG	21
#13	OSG Corporation	20
#14	TaeguTec Ltd.	20
#15	Mitsubishi Hitachi Tool Engineering, Ltd.	19
#16	Moldino Tool Engineering, Ltd.	19
#17	Hy-ko Products Company LLC	19
#18	Karsten Manufacturing Corporation	17
#19	Guehring KG	17
#20	Hartmetall-Werkzeugfabrik Paul Horn GmbH	17

Footprint here vs. claim strategy

Each dot is a leading B23C 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 B23C assignees by class footprint. Bubble size = patents in B23C. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near B23C's 2,322-grant footprint

Nationwide nearest neighbors for B23C (#353 of 670 by volume ; lead share 6.8%) - not the B23 parent-class siblings above.

Nearest by grant volume

B30B 2,314 C01F 2,333 B07C 2,293 G04B 2,356

Nearest by lead-assignee share

C09C 6.8% F23Q 6.8% B61H 6.8% B24B 6.8%

Questions about B23C

Which company holds the most patents in B23C?

Kennametal Inc. leads B23C with 158 patents (6.8% of the subclass). By PatentsView assignee type, foreign corporations account for 74% of class grants.

Which B23C assignees grew fastest recently?

Among assignees with ≥5 grants in B23C, AB Sandvik Coromant shows the highest company-wide grant multiple (17x: 0 grants in 2019–2021 → 17 in 2022–2024) while holding 5 patents in this subclass. Growth is company-wide, not class-only.

How does B23C compare inside parent class B23?

Inside B23 (Machine TOOLS; Metal-working NOT Otherwise Provided FOR), B23C ranks #6 of 9 subclasses by grant volume and holds 4.9% of the parent class total. The largest sibling is B23K (21,060 grants).

What to do with this data

B23C in context - here's where to go next.

Kennametal Inc. leads B23C with 158 grants in this class. See full portfolio
B23C ranks #353 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class B23, the largest sibling subclass is B23K with 21,060 grants. Explore B23K

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

Methodology - B23C figures are USPTO PatentsView granted-utility totals for this subclass (2,322 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.