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  • 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 1/40 - Direct resistance heating

Patent holdings for IPC class C21D 1/40

Total number of patents in this class: 161

10-year publication summary

20
15
12
11
5
6
3
10
5
8
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

Principal owners for this class

Owner
All patents
This class
Neturen Co., Ltd.
198
19
NHK Spring Co., Ltd.
1983
17
Chuo Hatsujo Kabushiki Kaisha
127
8
California Institute of Technology
4043
5
Sumitomo Heavy Industries, Ltd.
2110
5
Apple Inc.
58705
4
Asteer Co., Ltd.
10
4
NTN Corporation
4915
3
Gottfried Wilhelm Leibniz Universität Hannover
154
3
Institute for Basic Science
384
3
Nippon Steel Corporation
6843
3
Tokyo Rope Mfg. Co., Ltd.
66
3
TOYOTA JIDOSHA KABUSHIKI KAISHA (also trading as TOYOTA MOTOR CORPORATION)
12387
3
GM Global Technology Operations LLC
16106
2
Hyundai Motor Company
24602
2
The United States of America as represented by the Secretary of the Navy
2856
2
Sumitomo Wiring Systems, Ltd.
10987
2
Northwestern University
3540
2
Benteler Automobiltechnik GmbH
305
2
JFE Steel Corporation
7508
2
Other owners 67

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