CYLINDRICAL FORMED BODY MANUFACTURING METHOD, AND CYLINDRICAL FORMED BODY MANUFACTURED BY THE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method capable of efficiently performing the cold forging of a cylindrical formed body represented by a cold forged product of high rigidity, in particular, a high nut, etc., and the cylindrical formed body formed by the method.;SOLUTION: Stock steel materials 10A-10E are formed of stainless steel containing ≥0.02 wt.% carbon, the stock steel materials 10A-10E are housed in dies 3a-3e, the stock steel materials 10A-10E are subjected to composite extrusion or upsetting by punches 5a-5e having a forming space between the dies 3a-3e and themselves to obtain the cylindrical formed body having the cylindrical length larger than the outside diameter.;COPYRIGHT: (C)2002,JPO