To enable it to reduce an oil leakage in an oil seal shaft by installing the specified depth of a groove in a roller peripheral radius (R) surface of a burnishing tool burnishing this oil seal shaft, and forming an oil sum weir where a root part of working marks is not continued as a screw in time of burnishing.
A burnishing tool machines a work surface in a smooth state through the feed of a tool rest as pressing a roller 10 supported free of rotation by a shaft to a work surface (a turning surface or the like) in rotation. In this case, a groove 12 is installed in a peripheral radius (R) surface 11 of this roller 10, and the depth is made into a range of 0.8 to 3.2μm, while it is formed so as to have angle θ1 of 5 to 10 minutes to the axial orthogonal direction of the roller 10. At the time of burnishing, the roller peripheral radius (R) surface 11 and the groove 12 are transferred on the work surface where the roller 10 passed through, and two weirs 22a and 22b are formable so as to be traversed across a ridgeline 21 of working marks formed by the roller peripheral radius (R) surface 11, whereby the oil sump is partitioned off.
TANAKA KAZUHIKO
UCHIYAMA MITSUO
