Provided is a shaft member capable of minimizing the occurrence of noise
by positively attenuating vibration acting on a metal shaft member having
spline grooves and spiral grooves axially formed therein. To attain such
an object, a shaft member includes a metal shaft main body having a
hollow portion and a ceramic material serving as a vibration absorbing
member which fills the hollow portion of the shaft body with no gaps. The
ceramic material is filled into the hollow portion of the shaft main body
in a powder, granular, or fluid state, and formed within the hollow
portion into a shape matching the hollow portion.