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ABEC Tolerances

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Pacamor Kubar Bearings - PKB

Grades of Precision

PACAMOR KUBAR BEARINGS are manufactured to standard grades of precision with established tolerances for size and geometric accuracy. These standards are known as ABEC classes as set by the Annular Bearing Engineers Committee of the American Bearing Manufacturer's Association (ABMA). These standards are also accepted by (ANSI) American National Standards Institute and by international agreement for the standards developed by (ISO) International Organization of Standardization.

The ABEC scale is a system of rating the manufacturing tolerance of precision bearings. The system was developed by the Annular Bearing Engineering Council (ABEC), a division of the American Bearing Manufacturers' Association ABMA). The ABMA was formerly known as the Anti-Friction Bearing Manufacturers' Association. Bearings rated under the ABEC systems are typically called "precision bearings", with a rating or class from 1 to 9. ABEC 1 meets a looser tolerance and ABEC 9 meets high precision tight bearing tolerances. ABEC class is not to be confused with radial play, which is discussed under that section of our website.

For further assistance with bearing selection and design, please feel free to contact our engineering team or look at our online catalog .

ABEC Tolerances
All tolerances are in .0001 inches abec 1 abec 3p abec 5p abec 7p abec 9p
INNER RING (Bore Diameter < 0.7087 inches)  
Bore Tolerance +0/-3 +0/-2 +0/-2 +0/-2 +0/-2
Radial Runout (Bore 0 - 0.3937") 3 2 1.5 1 0.5
Radial Runout (Bore 0.3937 - 0.7087") 4 3 1.5 1 0.5
Width Tolerance +0/-50 +0/-50 +0/-10 +0/-10 +0/-10
Width Variation - - 2 1 0.5
Reference Runout with Bore (max) - - 3 1 0.5
Groove Runout with Reference Side (max) - - 3 1 0.5
Bore 2 Point Out of Round (max) - - 1 1 0.5
Bore Taper (max) - - 1 1 0.5
  
OUTER RING (OUTER Diameter < 0.875 inches)  
Outer Diameter Tolerance +0/-3 +0/-3 +0/-2 +0/-2 +0/-1
Radial Runout (max) 6 4 2 1.5 0.5*
Width Tolerance +0/-50 +0/-50 +0/-10 +0/-10 +0/-10
Width Variation - - 2 1 0.5
Flange Width Tolerance Limits - +0/-20 +0/-20 +0/-20 -
Flange Diameter Tolerance Limits - +50/-20 +0/-10 +0/-10 -
Groove Runout with Reference Side (max) - - 3 2 0.5*
Outside Cylindrical Surface
Runout with Reference Side (max)
- - 3 1.5 0.5

 

* For ABEC 9 Bearings with Outer Diameters from 0.787 to 0.875
O.D tolerance = +0 / -1.5
Radial Runout = 1
Groove Runout with Reference Side = 1