IPC Definitions - January 01, 2012
B21D 26/021 - Definition
This group covers:
Devices and methods for deforming sheet metal in the form of flat sheets or thin plates, whether layered or not, by applying fluid pressure.
Special rules of classification
When the invention is characterized by the shape of the bodies to be deformed in combination with a particular material feature of the bodies to be deformed, the invention shall also be classified in B21D 26/053 and subgroups thereof.