C21D 9/22
Heat treatment: for drills
Official title: for drills; for milling cutters; for machine cutting tools
C21D9/22 (Heat treatment: for drills) appears on 104 US grants and 88 published applications in this corpus.
Search patents in C21D- Granted patents
- 104
- Published applications
- 88
- Assignees
- 78
- Inventors
- 233
- Latest grant
- 1 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 0 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 1 | 0 |
| 1982 | 1 | 0 |
| 1983 | 2 | 0 |
| 1984 | 1 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 4 | 0 |
| 1988 | 3 | 0 |
| 1989 | 2 | 0 |
| 1990 | 1 | 0 |
| 1991 | 2 | 0 |
| 1992 | 1 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 2 | 0 |
| 1996 | 1 | 0 |
| 1997 | 2 | 0 |
| 1998 | 0 | 0 |
| 1999 | 3 | 0 |
| 2000 | 2 | 0 |
| 2001 | 2 | 1 |
| 2002 | 5 | 2 |
| 2003 | 3 | 3 |
| 2004 | 1 | 2 |
| 2005 | 3 | 2 |
| 2006 | 1 | 2 |
| 2007 | 1 | 0 |
| 2008 | 1 | 1 |
| 2009 | 1 | 8 |
| 2010 | 0 | 2 |
| 2011 | 4 | 4 |
| 2012 | 3 | 6 |
| 2013 | 1 | 3 |
| 2014 | 1 | 3 |
| 2015 | 6 | 9 |
| 2016 | 6 | 10 |
| 2017 | 3 | 4 |
| 2018 | 4 | 9 |
| 2019 | 3 | 0 |
| 2020 | 7 | 3 |
| 2021 | 2 | 2 |
| 2022 | 0 | 4 |
| 2023 | 3 | 5 |
| 2024 | 2 | 2 |
| 2025 | 2 | 1 |
| 2026 | 4 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Surface-hardened, rotationally symmetrical workpiece, hardening method and hardening apparatus1 Sep 2026US 12,723,286 B2Walzengiesserei Coswig GmbH
- Tool and manufacturing method of it21 Apr 2026US 12,605,782 B2Seco Tools AB
- Method of treating a cemented carbide mining insert10 Feb 2026US 12,545,977 B2Sandvik Mining and Construction Tools AB
- Free-cutting steel and method for manufacturing same13 Jan 2026US 12,522,906 B2Jfe Steel Corporation
- Stainless steel and a cutting tool body made of the stainless steel24 Jun 2025US 12,338,517 B2Uddeholms AB
- Method of producing a free-cutting steel14 Aug 2025US 2025/0257419 A1Jfe Steel Corporation
- Process for obtaining a fine-grained martensitic structure component15 Aug 2024US 2024/0271239 A1Danmarks Tekniske Universitet
- Tool and manufacturing method of it30 May 2024US 2024/0173787 A1Seco Tools AB
- Surface-hardened, rotationally symmetrical workpiece, hardening method and hardening apparatus2 Nov 2023US 2023/0349018 A1Walzengiesserei Coswig GmbH
- Free-cutting steel and method for manufacturing same22 Jun 2023US 2023/0193440 A1Jfe Steel Corporation
Most cited
By later US patents
- Differentially hardfaced rock bit86US 4,726,432 AHughes Tool Company - USA · 1988
- Process for laser hardfacing drill bit cones having hard cutter inserts54US 4,781,770 ASmith International, Inc. · 1988
- Surface decarburization of a drill bit51US 5,609,447 ARogers Tool Works, Inc. · 1997
- Heat management drilling system and method51US 6,374,932 B12002
- Laser-clad composite cutting tool and method42US 6,146,476 AAlvord-Polk, Inc. · 2000