the blacksmith operation, which is consisted in the
deformation of billet by partial sagging for the purpose of the creation of local thickenings
due to the decrease of the length of billet. V. is produced in
the heated or cold state. Hot v. is achieved in the horizontal forging machines. By hot
v. manufactures the forgings of gears, valves, springs, rings, rollers
and the like cold v. it is achieved on the cold-heading automata and
the presses. By cold v. manufactures bolts, rivets, etc. in
comparison with other processes of punching v. it is characterized by
high productivity and accuracy of forgings (without the burr).
Is spread v. with local contact resistance heating of billets in
the die in the electroupsetting machine, which makes it possible for one passage to obtain
thickenings of large volume.
Lit.: Suslov p. v., forging and
pressing equipment, M., 1956.
