survetöötluse (sepistamise) kujumuuteprotsess/-operatsioon – õõneskeha, nt rõnga läbimõõdu suurendamine ristlõikepinna vähendamise arvel (vrd pikivenitus; ristivenitus), forming a seamless metal ring by forging a pierced disk over a mandrel (or saddle), in which diameter of a ring is increased at the expense of its cross section (compare: drawing out; spreading)