B21H MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
Introduced: September 1968
Classification Context
- Section:
- PERFORMING OPERATIONS; TRANSPORTING
- Class:
- MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- Subclass:
- MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
Description
B21H encompasses mechanical metal-working processes that form specific finished metal articles or near-finished components through rolling operations, without material removal. The subclass covers techniques for manufacturing discrete objects such as screws, wheels, rings, barrels, balls, and similar items where rolling is the primary shaping method. This includes cold rolling, hot rolling, and thread rolling processes applied to achieve dimensional accuracy and desired material properties in the final product. Related forming operations are classified elsewhere—B21B covers flat-rolled products (strip, sheet, plate), while B21G addresses other metal-working methods like forging and bending.
Filing statistics
IPC subclass B21H recorded 9,223 patent applications worldwide between 2013 and 2023. Annual filings grew from 542 in 2013 to 1,037 in 2023 (+91%), peaking at 1,079 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
In class comparison
B21H ranks 7th of 9 subclasses with filings in B21, with 9,223 applications between 2013 and 2023, 1.4% of the class. Annual filings grew 91% from 2013 to 2023, below the class as a whole (+146%).
| Rank | Subclass | Title | Applications | Share |
|---|---|---|---|---|
| 1 | B21D, Working or Processing of Sheet Metal or Metal Tubes, Rods or Profiles Without Essentially Removing Material; Punching Metal | Working or Processing of Sheet Metal or Metal Tubes, Rods or Profiles Without Essentially Removing Material; Punching Metal | 351,007 | 53.1% |
| 2 | B21C, Manufacture of Metal Sheets, Wire, Rods, Tubes, Profiles or Like Semi-Manufactured Products Otherwise Than by Rolling; Auxiliary Operations Used in Connection With Metal-Working Without Essentially Removing Material | Manufacture of Metal Sheets, Wire, Rods, Tubes, Profiles or Like Semi-Manufactured Products Otherwise Than by Rolling; Auxiliary Operations Used in Connection With Metal-Working Without Essentially Removing Material | 84,269 | 12.8% |
| 3 | B21B, Rolling of Metal | Rolling of Metal | 71,906 | 10.9% |
| 4 | B21F, Working or Processing of Metal Wire | Working or Processing of Metal Wire | 67,229 | 10.2% |
| 5 | B21J, Forging; Hammering; Pressing Metal; Riveting; Forge Furnaces | Forging; Hammering; Pressing Metal; Riveting; Forge Furnaces | 53,883 | 8.2% |
| 6 | B21K, Making Forged or Pressed Metal Products, e.g. Horse-Shoes, Rivets, Bolts or Wheels | Making Forged or Pressed Metal Products, e.g. Horse-Shoes, Rivets, Bolts or Wheels | 18,766 | 2.8% |
| 7 | B21H | Making Particular Metal Objects by Rolling, e.g. Screws, Wheels, Rings, Barrels, Balls | 9,223 | 1.4% |
| 8 | B21L, Making Metal Chains | Making Metal Chains | 2,434 | 0.4% |
| 9 | B21G, Making Needles, Pins or Nails of Metal | Making Needles, Pins or Nails of Metal | 1,702 | 0.3% |
Source: EPO PATSTAT, worldwide filings
Related Keywords
6 direct subcodes
Child Classifications
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- B21H 1/00 Making articles shaped as bodies of revolution
- B21H 3/00 Making helical bodies or bodies having parts of helical shape
- B21H 5/00 Making gear wheels
- B21H 7/00 Making articles not provided for in groups , e.g. agricultural tools, dinner forks, knives, spoons
- B21H 8/00 Rolling metal of indefinite length in repetitive shapes specially designed for the manufacture of particular objects
- B21H 9/00 Feeding arrangements for rolling machines or apparatus manufacturing articles dealt with in this subclass
Top Applicants
Top 10 applicants by patent filingsfor class B21, 2013–2023, worldwide · Source: EPO PATSTAT
- JFE STEEL 2,318
- JFE STEEL JP 2,294
- POSCO (POHANG IRON AND STEEL COMPANY) KR 2,083
- NIPPON STEEL CORPORATION JP 1,650
- NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 1,631
- SMS GROUP DE 1,472
- BAOSHAN IRON & STEEL COMPANY 1,181
- SGCC(STATE GRID CORPORATION OF CHINA) 1,079
- ANHUI JIANGHUAI AUTOMOBILE 984
- HYUNDAI STEEL COMPANY KR 980