- 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 1/06 - Surface hardening
Patent holdings for IPC class C21D 1/06
Total number of patents in this class: 797
10-year publication summary
|
84
|
75
|
56
|
64
|
54
|
52
|
53
|
30
|
22
|
15
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| NTN Corporation | 4976 |
83 |
| Nippon Steel Corporation | 6238 |
74 |
| Nippon Steel & Sumitomo Metal Corporation | 1988 |
45 |
| JFE Steel Corporation | 6840 |
24 |
| Aisin AW Co., Ltd. | 2327 |
20 |
| Honda Motor Co., Ltd. | 25251 |
19 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2874 |
19 |
| NHK Spring Co., Ltd. | 1861 |
16 |
| JTEKT Corporation | 2491 |
13 |
| PARKER NETSUSHORI KOGYO Co., Ltd. | 35 |
12 |
| Hitachi, Ltd. | 15484 |
11 |
| Caterpillar Inc. | 9548 |
11 |
| Aktiebolaget SKF | 2945 |
11 |
| Dowa Thermotech Co., Ltd. | 44 |
11 |
| IHI Corporation | 3426 |
11 |
| Robert Bosch GmbH | 42689 |
10 |
| Aichi Steel Corporation | 380 |
10 |
| Daido Steel Co., Ltd. | 270 |
10 |
| NSK Ltd. | 2777 |
9 |
| IHI Machinery and Furnace Co., Ltd. | 79 |
9 |
| Other owners | 369 |