CPC Subgroup
B21J 5/10 Piercing billets (in combination with extrusion B21C23/00)
Full Title
Methods for forging, hammering, or pressing (for working sheet-metal or metal tubes, rods, or profiles B21D; for working wire B21F); Special equipment or accessories therefor > for performing particular operations > Piercing billets (in combination with extrusion B21C23/00)