Idler Drum Shaft for Delta or Rockwell 6 x 48 Inch vertical Belt and 123 Inch Belt Disc Sander Finishing Machines. Use with (2) 902-01-020-1227R Lock Nuts. The Shaft has been ground to tolerance using a centerless grinding process. Will work with all of your original Delta or Rockwell parts EXCEPT the older style fine thread jam nuts.Works with Model #'s 31-550 31-550 31-550 31-552 31-710 31-730 31-731 31-910 Renovo offers many other parts for Delta or Rockwell 6 x 48 Inch vertical Belt and 12 Inch Belt Disc Sander Finishing Machines!