Engineering Reference
Precision Ball & Roller Bearings
(Medium to Large Diameter)
Tolerances
NHBB manufactures bearings to a variety of ABEC tolerance levels. Our smaller thin section and torque tube series of bearings are manufactured to ABEC 5T and 7T tolerances as described in ABMA Std. 12.2. Larger diameter thin cross section bearings are manufactured to ABEC 1F, 3F, 5F or 7F tolerances as noted in ABMA Std. 26.2. Our metric series bearings are manufactured to ABEC/RBEC 1, 3, 5 or 7 tolerances as outlined in ABMA Std. 20.
Inner and Outer Ring Tolerances
The choice of precision level is dependent on the requirements of the application. The lower classes (ABEC 1 and 3) are suitable for applications with lower speed and accuracy needs. These bearings provide a more favorable cost-to-performance ratio. Applications with the need for higher speed, lower torque or greater positional accuracy will most likely require higher precision grades. Please contact HiTech’s Applications Engineering department; for assistance in selecting the proper tolerance class.
Table of Inner Ring Tolerances
Bore Size (mm) | Bore Diameter Tolerance ABEC/RBEC Class | Radial Runout Maximum ABEC/RBEC Class | Ring Width | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ABEC 1 & 3 | ABEC 5, 7 & 9 | Duplex | ||||||||||||
Over | Incl | 1 | 3 | 5 | 7 | 9 | 1 | 3 | 5 | 7 | 9 | Single | Single | Individual Ring |
- | 10 | .0003 | .0003 | .0002 | .00015 | .0001 | .0004 | .00025 | .00015 | .0001 | .00005 | .0047 | .0016 | .0098 |
10 | 18 | .0003 | .0003 | .0002 | .00015 | .0001 | .0004 | .0003 | .00015 | .0001 | .00005 | .0047 | .0031 | .0098 |
18 | 30 | .0004 | .0003 | .00025 | .0002 | .0001 | .0005 | .0003 | .00015 | .0001 | .0001 | .0047 | .0047 | .0098 |
30 | 50 | .00045 | .0004 | .0003 | .00025 | .0001 | .0006 | .0004 | .0002 | .00015 | .0001 | .0047 | .0047 | .0098 |
50 | 80 | .0006 | .00045 | .00035 | .0003 | .00015 | .0008 | .0004 | .0002 | .00015 | .0001 | .0059 | .0059 | .0098 |
80 | 120 | .0008 | .0006 | .0004 | .0003 | .0002 | .0010 | .0005 | .00025 | .0002 | .0001 | .0079 | .0079 | .0150 |
120 | 180 | .0010 | .0007 | .0005 | .0004 | .0003 | .0012 | .0007 | .0003 | .00025 | .00015 | .0098 | .0098 | .0150 |
180 | 250 | .0012 | .00085 | .0006 | .00045 | .0003 | .0016 | .0008 | .0004 | .0003 | .0002 | .0118 | .0118 | .0197 |
Measurement in inches.
Table of Outer Ring Tolerances
Outside Diameter (mm) | Outside Diameter Tolerance ABEC/RBEC Class | Radial Runout Maximum ABEC/RBEC Class | Ring Width | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ABEC 1 & 3 | ABEC 5, 7 & 9 | Duplex | ||||||||||||
Over | Incl | 1 | 3 | 5 | 7 | 9 | 1 | 3 | 5 | 7 | 9 | Single | Single | Individual Ring |
18 | 30 | .00035 | .0003 | .00025 | .0002 | .00015 | .0006 | .00035 | .00025 | .00015 | .0001 | .0047 | .0016 | .0098 |
30 | 50 | .00045 | .00035 | .0003 | .00025 | .00015 | .0008 | .0004 | .0003 | .0002 | .0001 | .0047 | .0031 | .0098 |
50 | 80 | .0005 | .00045 | .00035 | .0003 | .00015 | .0010 | .0005 | .0003 | .0002 | .00015 | .0047 | .0047 | .0098 |
80 | 120 | .0006 | .0005 | .0004 | .0003 | .0002 | .0014 | .0007 | .0004 | .00025 | .0002 | .0047 | .0047 | .0098 |
120 | 150 | .0007 | .0006 | .00045 | .00035 | .0002 | .0016 | .0008 | .00045 | .0003 | .0002 | .0059 | .0059 | .0098 |
150 | 180 | .0010 | .0007 | .0005 | .0004 | .0003 | .0018 | .0009 | .0005 | .0003 | .0002 | .0079 | .0079 | .0150 |
180 | 250 | .0012 | .0008 | .0006 | .00045 | .0003 | .0020 | .0010 | .0006 | .0004 | .0003 | .0098 | .0098 | .0150 |
250 | 315 | .0014 | .0010 | .0007 | .0005 | .0003 | .0024 | .0012 | .0007 | .00045 | .0003 | .0118 | .0118 | .0197 |
Measurement in inches.
Please note: Industry standards for tolerances are issued and maintained by the American Bearing Manufacturers Association (ABMA), of which NHBB is an active member. Standards are established with input from ABMA associated bearing technical committees, Annular Bearing Engineers’ Committee (ABEC), Roller Bearing Engineers’ Committee (RBEC), and engineers and managers from member bearing manufacturers.