- All sections
- C - Chemistrymetallurgy
- C21D - Modifying the physical structure of ferrous metalsgeneral devices for heat treatment of ferrous or non-ferrous metals or alloysmaking metal malleable, e.g. by decarburisation or tempering
- C21D 9/32 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for gear wheels, worm wheels, or the like
Patent holdings for IPC class C21D 9/32
Total number of patents in this class: 355
10-year publication summary
|
26
|
30
|
30
|
26
|
26
|
15
|
25
|
11
|
12
|
12
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Nippon Steel Corporation | 6482 |
36 |
| Nippon Steel & Sumitomo Metal Corporation | 1987 |
22 |
| JFE Steel Corporation | 7054 |
17 |
| Aisin AW Co., Ltd. | 2302 |
15 |
| Honda Motor Co., Ltd. | 25780 |
13 |
| Dowa Thermotech Co., Ltd. | 49 |
11 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2866 |
11 |
| NTN Corporation | 4969 |
6 |
| Komatsu Ltd. | 4621 |
6 |
| PARKER NETSUSHORI KOGYO Co., Ltd. | 35 |
6 |
| SANYO Special Steel Co., Ltd. | 230 |
6 |
| ZF Friedrichshafen AG | 7171 |
5 |
| ArcelorMittal | 2396 |
5 |
| Daido Steel Co., Ltd. | 276 |
5 |
| Toyota Motor Corporation | 33440 |
4 |
| Sumitomo Electric Industries, Ltd. | 15780 |
4 |
| Safran Transmission Systems | 321 |
4 |
| Sikorsky Aircraft Corporation | 1093 |
4 |
| Sumitomo Electric Sintered Alloy, Ltd. | 230 |
4 |
| The Timken Company | 360 |
4 |
| Other owners | 167 |