Skip to content
Search Classifications
Search for IPC and CPC classification codes or keywords
DIFF Main Group
B21K 21/00

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)

Introduced: September 1968

Title

Titles differ between systems:

IPC: Making hollow articles not covered by any single one of groups

CPC: 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)

Full Title

Full titles differ between systems:

IPC:

Making hollow articles not covered by any single one of groups

CPC:

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)

IPC and CPC are identically structured here. All 6 subcodes exist in both systems.

2 shared codes have differing titles between IPC and CPC.

Child Classifications

Navigate with arrow keys, Enter to open

  • B21K 21/02 Producing blanks in the shape of discs or cups as semifinished articles for making hollow articles, e.g. to be deep-drawn or extruded IPC+CPC Available in IPC and CPC
  • B21K 21/04 Shaping thin-walled hollow articles, e.g. cartridges IPC+CPC Available in IPC and CPC
  • B21K 21/06 Shaping thick-walled hollow articles, e.g. projectiles IPC+CPC Available in IPC and CPC
  • B21K 21/16 Remodelling hollow bodies with respect to the shape of the cross-section (remodelling end portions only B21K21/12) IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class B21,2013–2023, worldwide · Source: EPO PATSTAT

  1. JFE STEEL 2,318
  2. JFE STEEL JP 2,294
  3. POSCO (POHANG IRON AND STEEL COMPANY) KR 2,083
  4. NIPPON STEEL CORPORATION JP 1,650
  5. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 1,631
  6. SMS GROUP DE 1,472
  7. BAOSHAN IRON & STEEL COMPANY 1,181
  8. SGCC(STATE GRID CORPORATION OF CHINA) 1,079
  9. ANHUI JIANGHUAI AUTOMOBILE 984
  10. HYUNDAI STEEL COMPANY KR 980

Top Applicants (CPC)

Class B21,2013–2023, worldwide · Source: EPO PATSTAT

  1. JFE STEEL JP 2,667
  2. NIPPON STEEL CORPORATION JP 2,049
  3. POSCO (POHANG IRON AND STEEL COMPANY) KR 1,967
  4. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 1,800
  5. SMS GROUP DE 1,538
  6. JFE STEEL 1,150
  7. ARCELORMITTAL LU 1,142
  8. BAOSHAN IRON & STEEL COMPANY 821
  9. HYUNDAI STEEL COMPANY KR 808
  10. THYSSENKRUPP STEEL EUROPE DE 660