B21K 21/00
Making hollow articles not covered by a single preceding sub-group
Official title: Making hollow articles not covered by a single preceding sub-group (essentially from sheet-metal or uniform thin-walled tubes B21D, e.g. B21D41/00, B21D51/00)
B21K21/00 (Making hollow articles not covered by a single preceding sub-group) appears on 431 US grants and 312 published applications in this corpus.
Search patents in B21K- Granted patents
- 431
- Published applications
- 312
- Assignees
- 311
- Inventors
- 877
- Latest grant
- 11 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 5 | 0 |
| 1978 | 5 | 0 |
| 1979 | 2 | 0 |
| 1980 | 6 | 0 |
| 1981 | 5 | 0 |
| 1982 | 4 | 0 |
| 1983 | 3 | 0 |
| 1984 | 8 | 0 |
| 1985 | 7 | 0 |
| 1986 | 4 | 0 |
| 1987 | 4 | 0 |
| 1988 | 3 | 0 |
| 1989 | 9 | 0 |
| 1990 | 4 | 0 |
| 1991 | 6 | 0 |
| 1992 | 6 | 0 |
| 1993 | 8 | 0 |
| 1994 | 8 | 0 |
| 1995 | 8 | 0 |
| 1996 | 13 | 0 |
| 1997 | 10 | 0 |
| 1998 | 11 | 0 |
| 1999 | 10 | 0 |
| 2000 | 16 | 0 |
| 2001 | 8 | 3 |
| 2002 | 6 | 13 |
| 2003 | 14 | 17 |
| 2004 | 10 | 13 |
| 2005 | 5 | 16 |
| 2006 | 6 | 11 |
| 2007 | 9 | 11 |
| 2008 | 8 | 13 |
| 2009 | 10 | 8 |
| 2010 | 8 | 12 |
| 2011 | 8 | 12 |
| 2012 | 10 | 17 |
| 2013 | 6 | 17 |
| 2014 | 13 | 15 |
| 2015 | 17 | 22 |
| 2016 | 15 | 7 |
| 2017 | 19 | 12 |
| 2018 | 3 | 16 |
| 2019 | 11 | 11 |
| 2020 | 16 | 10 |
| 2021 | 9 | 14 |
| 2022 | 10 | 13 |
| 2023 | 15 | 9 |
| 2024 | 12 | 8 |
| 2025 | 9 | 8 |
| 2026 | 5 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- B21K 21/12Shaping end portions of hollow articles182
- B21K 21/08Shaping hollow articles with different cross-section in longitudinal direction112
- B21K 21/16Remodelling hollow bodies with respect to the shape of the cross-section49
- B21K 21/04Shaping thin-walled hollow articles43
- B21K 21/06Shaping thick-walled hollow articles34
- B21K 21/02Producing blanks in the shape of discs or cups as semifinished articles28
Recent patents
- Method for production of a steel tubular product, in particular an airbag tubular product, and a steel tubular product produced using this method, in particular an airbag tubular product11 Aug 2026US 12,703,021 B2Benteler Steel/Tube GmbH
- Headlight and display integrated stem of electric bicycle, and electric bicycle26 May 2026US 12,637,162 B2
- Equipment and method for forming a front toothing on an inner ring of a wheel hub12 May 2026US 12,623,273 B2Aktiebolaget Skf
- Method and tool for producing a base piece of a multi-part cartridge case, base piece and cartridge case14 Apr 2026US 12,601,573 B2Ruag Ammotec GmbH
- Tool and method for producing a projectile and projectile20 Jan 2026US 12,529,549 B2RWS GmbH
- Cookware surface8 Oct 2026US 2026/0305867 A1Imperial Great British Design Limited
- Equipment and method for forming a front toothing on an inner ring of a wheel hub23 Jul 2026US 2026/0208259 A1
- Extrusion molding method and extrusion molding apparatus of a differential thickness pipe having a solid part25 Jun 2026US 2026/0175277 A1Sango Co., Ltd.
- Stainless Steel Spray Boom for Aerial Spraying1 Jan 2026US 2026/0001089 A1Texas Transland LLC
- Long cartridge case11 Dec 2025US 2025/0375805 A1The National Machinery Company
Most cited
By later US patents
- Medical suturing device, a single-strike die mechanism, and a method of using said die mechanism for forming the medical suturing device158US 5,411,521 AAmerican Cyanamid Company · 1995
- Method of necking and impact extruded metal container103US 5,572,893 A1996
- Intermediate article used to form a bullet projectile or component and a finally formed bullet70US 5,259,320 ABarnes Bullets, Inc. · 1993
- Method of manufacturing a hollow point bullet65US 5,943,749 AThe Nippert Company · 1999
- Methods of manufacturing a bullet61US 5,131,123 ABarnes Bullets, Inc. · 1992