C21D 8/1277 involving a particular surface treatment
Introduced: January 2026
Full Title
Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment > during manufacturing of articles with special electromagnetic properties > involving a particular surface treatment
Classification Context
- Section:
- CHEMISTRY; METALLURGY
- Class:
- METALLURGY OF IRON
- Subclass:
- MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
Filing statistics
IPC C21D 8/1277 belongs to the parent subclass C21D, which recorded 149,911 patent applications worldwide between 2013 and 2023. Annual filings grew from 9,561 in 2013 to 16,467 in 2023 (+72%), peaking at 16,959 applications in 2020. The most active applicants in class C21 are JFE STEEL (7,470 applications), POSCO (POHANG IRON AND STEEL COMPANY) (4,615 applications) and JFE STEEL (4,538 applications).
Source: EPO PATSTAT, worldwide filings
Top Applicants
Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT
- JFE STEEL JP 7,470
- POSCO (POHANG IRON AND STEEL COMPANY) KR 4,615
- JFE STEEL 4,538
- NIPPON STEEL CORPORATION JP 4,536
- ARCELORMITTAL LU 2,597
- NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,241
- ANGANG STEEL COMPANY 2,126
- NSSMC (NIPPON STEEL & SUMITOMO METAL) 1,783
- BAOSHAN IRON & STEEL COMPANY 1,620
- HYUNDAI STEEL COMPANY KR 1,545