- 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: 818
10-year publication summary
|
75
|
56
|
64
|
54
|
52
|
53
|
30
|
23
|
23
|
26
|
| 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| NTN Corporation | 4914 |
80 |
| Nippon Steel Corporation | 6871 |
77 |
| Nippon Steel & Sumitomo Metal Corporation | 1981 |
45 |
| JFE Steel Corporation | 7527 |
28 |
| Aisin AW Co., Ltd. | 2254 |
19 |
| Honda Motor Co., Ltd. | 26025 |
18 |
| Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | 2836 |
18 |
| NHK Spring Co., Ltd. | 1983 |
16 |
| JTEKT Corporation | 2583 |
13 |
| Dowa Thermotech Co., Ltd. | 53 |
13 |
| PARKER NETSUSHORI KOGYO Co., Ltd. | 36 |
12 |
| Hitachi, Ltd. | 16094 |
11 |
| Robert Bosch GmbH | 44160 |
11 |
| Aktiebolaget SKF | 3128 |
11 |
| IHI Corporation | 3535 |
11 |
| Caterpillar Inc. | 10267 |
10 |
| Aichi Steel Corporation | 392 |
10 |
| Daido Steel Co., Ltd. | 284 |
10 |
| NSK Ltd. | 2834 |
9 |
| ArcelorMittal | 2672 |
9 |
| Other owners | 387 |