Shaft Requirements

BEARING MEDIUM SHAFT REQUIREMENTS
  Hardness Surface Finish
Teflon-Bronze Hard or Soft 16 RMS Min.
SAE 840 Bronze Min. hardness of 95 HRB (Rockwell B) 16 RMS Min.
Delrin Hard or Soft 16 RMS Min.
Needle-Roller Hardness of 58-64 HRC (Rockwell C) 16 RMS Min.