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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.

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.

Inner Ring Tolerances

Tolerances in Inches
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

Outer Ring Tolerances

Tolerances in Inches
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

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.