- All sections
- C - Chemistry; metallurgy
- C21D - Modifying the physical structure of ferrous metals; general devices for heat treatment of ferrous or non-ferrous metals or alloys; making metal malleable, e.g. by decarburisation or tempering
- C21D 9/28 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for plain shafts
Patent holdings for IPC class C21D 9/28
Total number of patents in this class: 148
10-year publication summary
|
8
|
9
|
13
|
11
|
17
|
5
|
6
|
8
|
8
|
6
|
| 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Nippon Steel Corporation | 5649 |
31 |
| NTN Corporation | 5008 |
16 |
| JFE Steel Corporation | 6067 |
6 |
| Nippon Steel & Sumitomo Metal Corporation | 1990 |
6 |
| Honda Motor Co., Ltd. | 24537 |
5 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2865 |
5 |
| NSK Ltd. | 2719 |
4 |
| Aubert & Duval | 106 |
4 |
| Daido Steel Co., Ltd. | 237 |
4 |
| V & M do Brasil S/A | 5 |
3 |
| Walzengießerei Coswig GmbH | 6 |
3 |
| Siemens AG | 24990 |
2 |
| Caterpillar Inc. | 8877 |
2 |
| Komatsu Ltd. | 4265 |
2 |
| Mitsubishi Hitachi Power Systems, Ltd. | 999 |
2 |
| SANYO Special Steel Co., Ltd. | 201 |
2 |
| Sumitomo Metal Industries, Ltd. | 453 |
2 |
| Beijing Huali Fine Chemical Co., Ltd. | 2 |
2 |
| Mitsubishi Power, Ltd. | 1680 |
2 |
| CRS Holdings, LLC | 156 |
2 |
| Other owners | 43 |