CPC technology class · B23
B23C — Milling
Milling. 2,322 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.
- 2,322
- US patents granted
- B23
- Parent CPC class
- 20
- Active assignees
- -12%
- 5-yr velocity
CPC subclass B23C — MILLING — covers 2,322 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records. This subclass sits within the broader CPC class B23 (MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR), one of roughly 250 top-level technology categories in the Cooperative Patent Classification system jointly maintained by the USPTO and the European Patent Office. At the subclass level, four-character codes like B23C give the most practical resolution for tracking a specific technology domain without losing sight of adjacent filings. Every grant here has been classified by a USPTO examiner based on the technical disclosure in the patent specification.
The competitive landscape in B23C is shaped by 20 distinct companies actively filing in this space. KENNAMETAL INC. leads with 158 patents, followed by KYOCERA Corporation at 4,151 grants and TUNGALOY CORPORATION at 207. Concentration at the top of the leaderboard indicates whether this technology area is dominated by a handful of incumbents or fragmented across many filers — a useful signal for investors evaluating competitive moats and for product teams mapping freedom-to-operate risk.
Filing trajectory matters as much as static counts. The yearly series on this page plots grants from 2015 through 2025, highlighting whether innovation in B23C is accelerating, plateauing, or cooling. Technology areas with rising post-2020 activity often reflect emerging markets or new platform shifts, while declining filings can signal mature domains where incremental improvement has slowed. Researchers, licensing professionals, and competitive-intelligence teams use these patterns — together with the top-assignee distribution — to decide where to invest, where to license, and where to avoid entanglement. All counts on this page come directly from USPTO PatentsView and reflect US granted utility patents only.
Is B23C innovation accelerating?
US utility-patent grants per year in B23C, 2015–2025 — recent five years are down 12% versus 2015–2019.
Who leads B23C?
The 12 most active assignees in MILLING — wider bars mean more grants
- Kennametal 512
KENNAMETAL INC.
512 patents
- Kyocera
KYOCERA Corporation
4,151 patents
- Tungaloy 207
TUNGALOY CORPORATION
207 patents
- Sumitomo Electric Har… 459
SUMITOMO ELECTRIC HARDMETAL CORP.
459 patents
- Iscar 195
ISCAR, LTD.
195 patents
- Sandvik Intellectual… 458
Sandvik Intellectual Property AB
458 patents
- Mitsubishi Materials 640
MITSUBISHI MATERIALS CORPORATION
640 patents
- The Hillman Group 126
THE HILLMAN GROUP, INC.
126 patents
- Seco Tools Ab 111
Seco Tools AB
111 patents
- Korloy 51
KORLOY INC.
51 patents
- Makino Milling Machine 136
MAKINO MILLING MACHINE CO., LTD.
136 patents
- Franz Haimer Maschine… 57
Franz Haimer Maschinenbau KG
57 patents
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
| Rank | Company | Patents in B23C |
|---|---|---|
| #1 | KENNAMETAL INC. | 512 |
| #2 | KYOCERA Corporation | 4,151 |
| #3 | TUNGALOY CORPORATION | 207 |
| #4 | SUMITOMO ELECTRIC HARDMETAL CORP. | 459 |
| #5 | ISCAR, LTD. | 195 |
| #6 | Sandvik Intellectual Property AB | 458 |
| #7 | MITSUBISHI MATERIALS CORPORATION | 640 |
| #8 | THE HILLMAN GROUP, INC. | 126 |
| #9 | Seco Tools AB | 111 |
| #10 | KORLOY INC. | 51 |
| #11 | MAKINO MILLING MACHINE CO., LTD. | 136 |
| #12 | Franz Haimer Maschinenbau KG | 57 |
| #13 | OSG CORPORATION | 68 |
| #14 | TaeguTec Ltd. | 64 |
| #15 | MITSUBISHI HITACHI TOOL ENGINEERING, LTD. | 38 |
| #16 | MOLDINO TOOL ENGINEERING, LTD. | 28 |
| #17 | HY-KO PRODUCTS COMPANY LLC | 25 |
| #18 | Karsten Manufacturing Corporation | 1,177 |
| #19 | Guehring KG | 38 |
| #20 | Hartmetall-Werkzeugfabrik Paul Horn GmbH | 37 |
About This Class
CPC subclass B23C belongs to class B23.
2,322 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.
Frequently Asked Questions
What is CPC class B23C?
How many patents have been filed in B23C?
Which company holds the most patents in B23C?
How is patent data for B23C collected?
What is the difference between CPC class and subclass?
Learn More
Explore the patent dataset
Read our methodology — how this data is sourced, computed, and verified.