Patent ID: 8678653
Filing Date: 2014-03-25
Classification: B21K,B24B,F16C,Y10T

Abstract:
1. A stainless steel shaft member for a fluid lubrication bearing apparatus, the stainless steel shaft member comprising: a shaft portion having a threaded hole formed on one end portion of said shaft portion and a radial bearing face facing a radial bearing gap formed on an outer periphery of said shaft portion, wherein said threaded hole has a prepared hole formed by a forging process, and a thread portion formed on an opening side of said prepared hole by a rolling process, said prepared hole comprises a conical surface and a cylinder face which is disposed on an opening side of said conical surface, said cylinder face is smoothly continuous with said conical surface via a radially curved surface, a bottom of said prepared hole is formed at a position closer to an opening side of said threaded hole in an axial direction than said radial bearing face, and said thread portion is formed on said cylinder face.