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IPC Subgroup
B21L 3/04

by making use of forge or pressure welding

Introduced: September 1968

Last revised: January 2006

Full Title

Making chains or chain links by bending the chain links or link parts and subsequently welding or soldering the abutting ends > Machines or devices for welding chain links > by making use of forge or pressure welding

Classification Context

Section:
PERFORMING OPERATIONS; TRANSPORTING
Class:
MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
Subclass:
MAKING METAL CHAINS

Filing statistics

IPC B21L 3/04 belongs to the parent subclass B21L, which recorded 2,434 patent applications worldwide between 2013 and 2023. Annual filings grew from 138 in 2013 to 225 in 2023 (+63%), peaking at 354 applications in 2020. The most active applicants in class B21 are JFE STEEL (2,318 applications), JFE STEEL (2,294 applications) and POSCO (POHANG IRON AND STEEL COMPANY) (2,083 applications).

Source: EPO PATSTAT, worldwide filings

Top Applicants

Top 10 applicants by patent filingsfor 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