Convert a two-step superfinishing process, to a single stone process for honing the Cone raceway on a TRB.  Additional goal to obtain a more consistent visual appearance and lower the superfinishing cost per unit.


Single stone superfinishing process




60-62 R/C

Stock Removal

5 – 8 µm on diameter


Honing Oil

Finish Requirements

0.2 µm Ra Max, Statistically < 0.15 µm Ra

Machine Setup

1 stone XBL-403W, .500 x .487 x 4.0”. Two sets of parameters, Rough and Finish. Cycle Time < 4.5 seconds after break in.


This was significant cost savings by going to a single tool process and, a reduction in cycle time. There was also an improved visual appearance, which was gave a more homogenous look part to part.

Additional cost per unit savings were obtained by converting from a conventional vitrified Aluminum Oxide stone, to an induced porosity X-SERIES Aluminum Oxide stone. Average stone wear per part was reduced by approximately 40%, leading to longer tool life. Average Ra’s were lowered from a 0.095 µm Ra to 0.0795 Ra or, a 16% improvement. There was also a reduction in scrap that offered greater savings.