Kalish & Gilster
Plastic working method for holed metal parts
 A plastic working method for making a holed metal part. A holed blank with a through hole is placed at the center in a die member which has a die and a container continuing to the die. The die is pushed toward a punch, inserting into the through hole a first portion of a mandrel which has cross sections with at least two different cross-sectional areas. The blank is compressed by a counter punch fitting with the container and a punch pressing the die end face of the die member toward the counter punch to cause the blank plasticly to flow into a space formed between the die hole of the die and the first portion of the mandrel and while applying a compressive force to the blank by the punch and the counter punch, pulling out the first portion of the mandrel out of the blank through hole while inserting a further portion of the mandrel into the through hole so as plastically to flow the blank into a gap between the first portion of the mandrel and the through hole. Other embodiments of the method are also disclosed. 
Aida Engineering, Ltd.
B B
B21K B21K
inventional inventional
Kazuto Takashi Toshio
Kobayashi Nakano Suzuki