- 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 9/28 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for plain shafts
Patent holdings for IPC class C21D 9/28
Total number of patents in this class: 157
10-year publication summary
|
9
|
13
|
11
|
17
|
5
|
6
|
9
|
8
|
10
|
10
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Nippon Steel Corporation | 6207 |
29 |
| NTN Corporation | 4983 |
17 |
| JFE Steel Corporation | 6816 |
6 |
| Nippon Steel & Sumitomo Metal Corporation | 1988 |
6 |
| Honda Motor Co., Ltd. | 25174 |
5 |
| NSK Ltd. | 2770 |
4 |
| ArcelorMittal | 2272 |
4 |
| Aubert & Duval | 111 |
4 |
| Daido Steel Co., Ltd. | 269 |
4 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2876 |
4 |
| V & M do Brasil S/A | 5 |
3 |
| Walzengießerei Coswig GmbH | 6 |
3 |
| CRS Holdings, LLC | 155 |
3 |
| Rtx Corporation | 9332 |
3 |
| Siemens AG | 24520 |
2 |
| Caterpillar Inc. | 9530 |
2 |
| Komatsu Ltd. | 4528 |
2 |
| Hyundai Steel Company | 426 |
2 |
| Mitsubishi Hitachi Power Systems, Ltd. | 993 |
2 |
| POSCO Co., Ltd. | 1559 |
2 |
| Other owners | 50 |