A micro-roll forming device for providing a cylindrical blank metal
article with a minute convexoconcave bearing surface, comprises a powered
article holding structure that, when energized, rotates the cylindrical
blank metal article about its axis; a forming tool that includes a form
roller with a corrugated circular ridge; a tool holding structure that
holds the forming tool in such a manner that the corrugated circular
ridge of the form roller is directed toward and in contact with an outer
surface of the cylindrical blank metal article rotatably held by the
article holding structure; a biasing member that is incorporated with the
tool holding structure to press the form roller against the outer surface
of the cylindrical blank metal article with a given pressing force; and a
powered moving structure that, when energized, moves at least one of the
article holding structure and the tool holding structure in such a manner
that the selected one moves in both a first direction perpendicular to an
axis of the unselected one and a second direction parallel with the axis
of the unselected one.