C21D 9/40
Heat treatment: for rings
Official title: for rings; for bearing races
C21D9/40 (Heat treatment: for rings) appears on 418 US grants and 485 published applications in this corpus.
Search patents in C21D- Granted patents
- 418
- Published applications
- 485
- Assignees
- 189
- Inventors
- 1,052
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 2 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 1 | 0 |
| 1986 | 2 | 0 |
| 1987 | 3 | 0 |
| 1988 | 1 | 0 |
| 1989 | 3 | 0 |
| 1990 | 3 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 1 | 0 |
| 1994 | 5 | 0 |
| 1995 | 7 | 0 |
| 1996 | 5 | 0 |
| 1997 | 6 | 0 |
| 1998 | 5 | 0 |
| 1999 | 9 | 0 |
| 2000 | 12 | 0 |
| 2001 | 11 | 2 |
| 2002 | 10 | 4 |
| 2003 | 13 | 10 |
| 2004 | 5 | 11 |
| 2005 | 6 | 11 |
| 2006 | 8 | 9 |
| 2007 | 3 | 14 |
| 2008 | 4 | 6 |
| 2009 | 4 | 22 |
| 2010 | 10 | 20 |
| 2011 | 5 | 26 |
| 2012 | 14 | 23 |
| 2013 | 20 | 25 |
| 2014 | 14 | 28 |
| 2015 | 20 | 33 |
| 2016 | 25 | 53 |
| 2017 | 28 | 23 |
| 2018 | 29 | 22 |
| 2019 | 26 | 27 |
| 2020 | 17 | 23 |
| 2021 | 17 | 13 |
| 2022 | 14 | 22 |
| 2023 | 11 | 17 |
| 2024 | 14 | 21 |
| 2025 | 6 | 16 |
| 2026 | 11 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Workpiece holding device6 Oct 2026US 12,753,453 B2Aktiebolaget Skf
- Bearing part22 Sep 2026US 12,742,476 B2Ntn Corporation
- Highly corrosion-resistant stainless steel component and method of manufacturing same, method of heat-treating stainless steel component, and rolling bearing and method for manufacturing same25 Aug 2026US 12,716,109 B2MINEBEA MITSUMI Inc.
- Method of heat treating a steel component18 Aug 2026US 12,709,781 B2Aktiebolaget Skf
- Induction hardening system7 Apr 2026US 12,595,524 B2Aktiebolaget Skf
- One-step carbo-nitro-austempering process for forming steel bearings10 Sep 2026US 2026/0265851 A1GM Global Technology Operations LLC
- Induction hardening treatment method and application for large bearing ring3 Sep 2026US 2026/0258521 A1
- Method for producing a rolling bearing component21 May 2026US 2026/0139708 A1Schaeffler Technologies AG & Co. KG
- Thin section bearing and computer tomograph having a thin section bearing of this type29 Jan 2026US 2026/0029021 A1Schaeffler Technologies AG & Co. KG
- Quenching method and restraint quenching device18 Dec 2025US 2025/0382678 A1Nsk Ltd.
Most cited
By later US patents
- Corrosion and wear resistant alloy88US 6,702,905 B1L. E. Jones Company · 2004
- Ultrasonic impact machining of body surfaces to correct defects and strengthen work surfaces72US 6,932,876 B1U.I.T., L.L.C. · 2005
- Ball-and-roller bearing41US 5,338,377 ANsk Ltd. · 1994
- Rolling bearing36US 4,930,909 ANippon Seiko Kabushiki Kaisha · 1990
- Cobalt-rich wear resistant alloy and method of making and use thereof35US 7,754,143 B2L. E. Jones Company · 2010