Cookies on the SKF website

We use cookies to ensure that we give you the best experience on our websites and web applications. By continuing without changing your browser settings, we assume you give your consent to receive cookies. However, you can change your browser cookie setting at any time.

Bearing data

  • (R)NA 22 designs
    ISO 15:2011, dimension series 22, except for the outer ring width
  • NATR, NATV, NUTR .. A, PWTR designs
    ISO 7063:2003 and ANSI/ABMA Standard 18.1-1982 (where standardized)
  • (R)STO
    Not standardized
Profile of the outer ring running surface
  • (R)STO, (R)NA 22, NATR, NATV designs
    Radius = 500 mm
  • NNTR design
    D ≤ 260 mm → Radius = 10 000 mm
    D ≥ 290 mm → Radius = 15 000 mm
  • NATR .. PPA, NATV .. PPA, NUTR .. A, PWTR designs
    Improved crowned profile for better load distribution, higher stiffness and reduced wear

For additional
(→ Tolerances)

Normal, except:

  • diameter of the crowned running surface, NNTR design: h10
  • diameter of the crowned running surface, other designs: 0/–0,05 mm
  • width B, NNTR design: 0/–0,5 mm
  • width B, NATR, NATV, NUTR .. A, PWTR designs: h12
  • inside diameter Fw, RSTO, RNA 22 designs: F6

Values for Normal tolerance class: ISO 492:2014 (table 1).

Values for ISO tolerance classes h7, h9, h10, h12 and F6: table 2

Internal clearance
  • STO and NA 22 designs
  • Other designs
    Between C2 and Normal

Values: ISO 5753-1:2009: table 3
Values are valid for unmounted bearings under zero measuring load.
Defect frequencies
Defect frequencies can be calculated using the tools available at SKF Bearing Calculator 
SKF logo