CPC Subgroup
B21B 13/20 for planetary rolling
Full Title
Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories (B21B17/00 - B21B23/00 take precedence) > for step-by-step or planetary rolling; (methods B21B1/42; making tubes by pilgrim-step rolling B21B21/00) > for planetary rolling