Provided is a roller burnishing tool device including a shank; a housing connected to the shank, a connected position of the housing relative to the shank being adjustable; a roller support member supported to be capable of rotating relative to the housing and attached to follow a movement of the housing in a case of adjusting the connected position; tapered rollers supported by the roller support member; a mandrel having a tapered portion matched with the tapered rollers and movable relative to the roller support member; and a tool diameter following mechanism connecting the shank and the mandrel, having a lead groove formed spirally in a front portion of the shank, a pin member capable of moving along the lead groove, a pin member insertion hole formed in the mandrel to insert the pin member therein, and a biasing unit biasing the mandrel forward.

A method for chipless machining of a surface region of a rolling-element bearing ring includes rotating the rolling-element bearing ring relative to a first tool having a first tool tip and a second tool having a second tool tip, positioning the first and second tool tips at start positions at first and second opposite axial ends of the surface region, and moving the first and second tools in opposite axial directions such that the first tool tip follows a first helical or spiral path on the surface region and the second tool tip follows a second helical or spiral path on the surface region, the first and second paths crossing at multiple points within an overlap region located between axial ends of the surface regions.