CPC Subgroup
C21B 7/04 with special refractories (refractory materials C04B)
Full Title
Blast furnaces (lifts associated with blast furnaces B66B9/06) > with special refractories (refractory materials C04B)
Filing statistics
CPC C21B 7/04 belongs to the parent subclass C21B, which recorded 18,493 patent applications worldwide between 2013 and 2023. Annual filings grew from 1,109 in 2013 to 2,100 in 2023 (+89%), peaking at 2,528 applications in 2022. 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
1 direct subcode
Child Classifications
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- C21B 7/06 Linings for furnaces
Top Applicants
Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT
- JFE STEEL JP 8,270
- NIPPON STEEL CORPORATION JP 5,222
- POSCO (POHANG IRON AND STEEL COMPANY) KR 4,824
- JFE STEEL 3,311
- ARCELORMITTAL LU 3,239
- NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,659
- HYUNDAI STEEL COMPANY KR 1,492
- ANGANG STEEL COMPANY 1,318
- BAOSHAN IRON & STEEL COMPANY 1,233
- KOBE STEEL JP 1,228