DIFF Subgroup
B21D 31/046 Full Title
Other methods for working sheet metal, metal tubes, metal profiles (deforming one surface of tubes helically by rolling B21H3/00; upsetting B21J5/08; working metal by removing material therefrom B23; embossing B44B) > Expanding other than provided for in groups B21D1/00 - B21D28/00, e.g. for making expanded metal (B21D47/00 takes precedence; enlarging tube ends B21D41/02)