Manufacturing method of steel ball for rolling bearing

摘要

A method of manufacturing a steel ball for a rolling bearing, said method comprising: a molding step of forming a steel wire cut at a predetermined length into a raw ball having a band portion by a pair of molding forms having respectively hemispherical concave portions and relief grooves in peripheries of said concave portions on their respective opposing faces, said band portion being formed on a surface of said raw ball along said relief grooves by compressing said steel wire by said molding forms in a state in which both ends of said steel wire are sandwiched between said concave portions; and a tumbler working step of removing said band portion from the surface of the raw ball by tumbling.