METHOD FOR MAKING HEAD OF ANNULAR TYPE NUT WRENCH AND METHOD FOR MAKING BLANK FOR PERFORMING IT Russian patent published in 2003 - IPC

FIELD: plastic metal working, namely manufacture of tools by forging and forming operations. SUBSTANCE: measured-length blank of initial material in the form of rod is upset in closed die set until height h. Then central opening is drilled in blank; said opening is turned by cone in order to form truncated cone with height h. Diameters of upper and lower bases of cone are determined with use of expressions given in description of invention. Then blank is heated and it is placed in piercing die set in such a way that upper base of cone is arranged at inlet side of blank for piercing. Opening is pierced during two passes: rough and finish. Piercing die set has surface coinciding with inner surface of closed die set for upsetting. Parting plane of upsetting die set is matched with mean portion of blank. EFFECT: enlarged manufacturing possibilities of method, enhanced quality of articles. 4 cl, 6 dwg