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CPC Subgroup
C21D 9/20

for blades for skates

Full Title

Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor > for blades for skates

Filing statistics

CPC C21D 9/20 belongs to the parent subclass C21D, which recorded 112,271 patent applications worldwide between 2013 and 2023. Annual filings grew from 6,047 in 2013 to 10,554 in 2023 (+75%), peaking at 12,689 applications in 2020. The most active applicants in class C21 are JFE STEEL (8,270 applications), NIPPON STEEL CORPORATION (5,222 applications) and POSCO (POHANG IRON AND STEEL COMPANY) (4,824 applications).

Source: EPO PATSTAT, worldwide filings

Top Applicants

Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT

  1. JFE STEEL JP 8,270
  2. NIPPON STEEL CORPORATION JP 5,222
  3. POSCO (POHANG IRON AND STEEL COMPANY) KR 4,824
  4. JFE STEEL 3,311
  5. ARCELORMITTAL LU 3,239
  6. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,659
  7. HYUNDAI STEEL COMPANY KR 1,492
  8. ANGANG STEEL COMPANY 1,318
  9. BAOSHAN IRON & STEEL COMPANY 1,233
  10. KOBE STEEL JP 1,228