Tolerances
For more than thirty years, NHBB has been an active member in the American Bearing Manufacturers Association (ABMA) and its associated ball bearing technical committee, the Annular Bearing Engineers’ Committee (ABEC). The ABEC tolerances listed in the attached document are current as of this posting. These tolerances are reviewed regularly and updated as required. The ABMA Standards may be obtained by contacting: ABMA, 2025 M Street, NW, Suite 800, Washington, DC 20036.
Inner Ring*
| Characteristic | ABEC 1 | ABEC 3P | ABEC 5P | ABEC 7P | ABEC 9P |
|---|---|---|---|---|---|
| Bore tolerance limits | +.0000 –.0003 |
+.0000 –.0002 |
+.0000 –.0002 |
+.0000 –.0002 |
+.0000 –.0001 |
| Bore 2 pt. out of roundness | — | — | .0001 | .0001 | .00005 |
| Bore taper | — | — | .0001 | .0001 | .00005 |
| Radial runout | .0004 | .0002 (1) | .00015 | .0001 | .00005 |
| Width variation | — | — | .0002 | .0001 | .00005 |
| Bore runout with face | — | — | .0003 | .0001 | .00005 |
| Race runout with face . | — | — | .0003 | .0001 | .00005 |
*Measurement in inches.
(1) Add .0001 to the tolerance if bore size is over 10mm (.3937 inch).
Outer Ring*
| CHARACTERISTIC | CONFIGURATION | SIZE RANGE | ABEC 1 | ABEC 3P | ABEC 5P | ABEC 7P | ABEC 9P |
|---|---|---|---|---|---|---|---|
| Mean O.D. tolerance limits | All | 0-18 mm (0-.7086 inch) |
+.0000 –.0003 |
+.0000 –.0003 |
+.0000 –.0002 |
+.0000 –.0002 |
+.0000 –.0001 |
| over 18-30 mm (.7086-1.1181 inch) |
+.0000 –.0004 |
+.0000 –.0003 |
+.0000 –.0002 |
+.0000 –.0002 |
+.0000 –.00015 |
||
| Maximum O.D. tolerance limits | Open | 0-18 mm (0-.7086 inch) |
+.0001 –.0004 |
+.0001 –.0004 |
+.0000 –.0002 |
+.0000 –.0002 |
+.0000 –.0001 |
| over 18-30 mm (.7086-1.1811 inch) |
+.0001 –.0005 |
+.0001 –.0004 |
+.0000 –.0002 |
+.0000 –.0002 |
+.0000 –.00015 |
||
| Shielded | 0-18 mm (0-.7086 inch) |
+.0002 –.0005 |
+.0002 –.0005 |
+.00004 –.00024 |
+.00004 –.00024 |
— — |
|
| over 18-30 mm (.7086-1.1811 inch) |
+.0002 –.0006 |
+.0002 –.0005 |
+.00004 –.00024 |
+.00004 –.00024 |
|||
| O.D. 2 pt. out of roundness | Open | 0-18 mm | — | — | .0001 | .0001 | .00005 |
| Open | over 18-30 mm | — | — | .0001 | .0001 | .00008 | |
| Shielded | 0-30 mm | — | — | .0002 | .0002 | — | |
| O.D. taper | All | 0-18 mm | — | — | .0001 | .0001 | .0005 |
| All | over 18-30 mm | — | — | .0001 | .0001 | .0008 | |
| Shielded | 0-30 mm | — | — | .0002 | .0002 | — | |
| Radial runout | All | 0-18 mm | .0006 | .0004 | .0002 | .00015 | .00005 |
| All | over 18-30 mm | .0006 | .0004 | .0002 | .00015 | .0001 | |
| Width variation | All | 0-30 mm | — | — | .0002 | .0001 | .00005 |
| O.D. runout with face | All | 0-30 mm | — | — | .0003 | .00015 | .00005 |
| Race runout with face | Plain | 0-18 mm | — | — | .0003 | .0002 | .00005 |
| Plain | over 18-30 mm | — | — | .0003 | .0002 | .0001 | |
| Flanged | 0-30 mm | — | — | .0003 | .0003 | — | |
| Flange width tolerance limits | — — |
— — |
+.0000 –.0020 |
+.0000 –.0020 |
+.0000 –.0020 |
— — |
|
| Flange diameter tolerance limits | — — |
— — |
+.0050 –.0020 |
+.0000 –.0010 |
+.0000 –.0010 |
— — |
*Measurement in inches, unless otherwhie indicated.
Ring Width*
| CHARACTERISTIC | CONFIGURATION | ABEC 1 | ABEC 3P | ABEC 5P | ABEC 7P | ABEC 9P |
|---|---|---|---|---|---|---|
| Width | Single bearing | +.000 | +.000 | +.000 | +.000 | +.000 |
| –.005 | –.005 | –.001 | –.001 | –.001 | ||
| Duplex pair | — | — | +.000 | +.000 | +.000 | |
| — | — | –.015 | –.015 | –.015 |
*Measurement in inches.