Skip to content
Search Classifications
Search for IPC and CPC classification codes or keywords
CPC Subgroup
C21D 1/50

Oil baths

Full Title

General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering > Methods of heating (C21D1/06 takes precedence) > in heat-treatment baths > Oil baths

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