- 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 1/06 - Surface hardening
Patent holdings for IPC class C21D 1/06
Total number of patents in this class: 783
10-year publication summary
|
60
|
84
|
75
|
56
|
64
|
54
|
52
|
51
|
29
|
9
|
| 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| NTN Corporation | 5008 |
81 |
| Nippon Steel Corporation | 5649 |
73 |
| Nippon Steel & Sumitomo Metal Corporation | 1990 |
45 |
| JFE Steel Corporation | 6067 |
24 |
| Aisin AW Co., Ltd. | 2430 |
22 |
| Honda Motor Co., Ltd. | 24537 |
19 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2865 |
19 |
| NHK Spring Co., Ltd. | 1657 |
15 |
| Aktiebolaget SKF | 2700 |
13 |
| JTEKT Corporation | 2423 |
12 |
| PARKER NETSUSHORI KOGYO Co., Ltd. | 33 |
12 |
| Hitachi, Ltd. | 16452 |
11 |
| Caterpillar Inc. | 8877 |
11 |
| Dowa Thermotech Co., Ltd. | 41 |
11 |
| IHI Corporation | 3268 |
11 |
| Daido Steel Co., Ltd. | 237 |
10 |
| NSK Ltd. | 2719 |
9 |
| Aichi Steel Corporation | 333 |
9 |
| IHI Machinery and Furnace Co., Ltd. | 79 |
9 |
| Robert Bosch GmbH | 40953 |
8 |
| Other owners | 359 |