FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES

Introduced: September 1968

Classification Context

Section:: PERFORMING OPERATIONS; TRANSPORTING
Class:: MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
Subclass:: FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES

Description

B21J covers mechanical metal-working processes that shape metal through deformation without material removal, including forging, hammering, pressing, and riveting operations. This classification encompasses the machinery, tools, and furnaces used in these processes, such as forging presses, hammers, dies, and the heating equipment necessary for hot-working metals. It applies to both manual and automated systems for cold and hot forming of metals into desired shapes, as well as the assembly of metal components through riveting. Adjacent classifications B21B (rolling) and B21D (sheet-metal working) address rolling and shearing/bending processes respectively, distinguishing them from the compressive deformation methods covered here.

Filing statistics

IPC subclass B21J recorded 53,883 patent applications worldwide between 2013 and 2023. Annual filings grew from 2,638 in 2013 to 6,521 in 2023 (+147%), peaking at 6,614 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

B21J ranks 5th of 9 subclasses with filings in B21, with 53,883 applications between 2013 and 2023, 8.2% of the class. Annual filings grew 147% from 2013 to 2023, above the class as a whole (+146%).

Subclasses of class B21 by patent applications, 2013–2023
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	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	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

CIRCLETSDRIFT(S)perforating or DRIFTING metal by forgingFORGING(S)joining by FORGING(S)HAMMERING metalJOINING metal parts together by forging, pressing or rivetingdrifting or PIERCING of metalshaping metal by PRESSINGSTAMPING by forging; stamps thereforSWAGING metalUPSETTING metal

10 direct subcodes

Child Classifications

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B21J 1/00 Preparing metal stock
B21J 11/00 Forging hammers combined with forging presses; Forging machines with provision for hammering and pressing
B21J 13/00 Details of machines for forging, pressing, or hammering
B21J 15/00 Riveting
B21J 17/00 Forge furnaces
B21J 19/00 Blacksmiths' requisites not otherwise provided for
B21J 3/00 Lubricating during forging or pressing
B21J 5/00 Methods for forging, hammering, or pressing; Special equipment or accessories therefor
B21J 7/00 Hammers; Forging machines with hammers or die jaws acting by impact
B21J 9/00 Forging presses

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