Our Tolerance Rings

BN Rings

BN-on-shaft

BN style rings have a free-state diameter smaller than the shaft diameter over which they are to be installed, so that when mounted to the shaft the rings conform to and become self-retaining on the shaft. If used with the centered or half-centered arrangement, the ring will snap into the groove and no further handling of the ring is necessary. If used with the free arrangement, the ring must be axially supported during assembly of the mating parts.

The BN ring is cut to fit inside a nominal circumference. Examples for use of the BN ring include mounting a bearing inner race to a shaft, or assemblies in which modification of the shaft is more practical than modifying the bore of the outer member.

Typical Applications for BN Rings

Standard BN Ring Size Chart

Below is our detailed chart of BN type rings, designed for typical bearing sizes. We keep many of these in stock, however, we often do custom ring development for specific needs. For anything not shown below, please fill out the New Project Information Form below, and we’ll work with you to develop a ring that meets or exceeds your needs.

BN RINGS DIAMETRAL 1
CLEARANCE
 TYPICAL BORE
FOR TORQUE
Typical Bearing Bore
For Bearing Mount
d
nominal
d
(in)
7/2
(in)
Part Numberd min
(in)
D max
(in)
G1
(in)
G2
(in)
Radial Capacity/
(lbs)
Torque Capacity
@ G13
(in-lbs)
TC
(in-lbs)
D min
(in)
D max
(in)
Dmin
(in)
D max
(in)
3/160.1880.250BN018025C0.1490.1890.0320.0395031.80.1530.1550.1490.150
5 mm0.1970.236BN5X6C0.1590.1980.0320.03950320.1620.1640.1590.160
6 mm0.2360.236BN6X6C0.1980.2370.0320.03985420.2010.2030.1980.200
1/40.2500.250BN025025C0.2110.2510.0320.039105740.2150.2170.2110.213
5/160.3130.250BN031025C0.2540.3140.0480.058551180.2620.2640.2540.256
8 mm0.3150.197BN8X5S0.2570.3160.0480.058125950.2640.2660.2570.259
3/80.3750.250BN037025S0.3170.3760.0480.05819021120.3230.3260.3170.320
10 mm0.3940.276BN10X7S0.3360.3950.0480.05820024170.3420.3450.3360.339
12 mm0.4720.197BN12X5S0.4140.4730.0480.05820031180.4200.4230.4140.417
1/20.5000.250BN050025S0.4420.5010.0480.05824037210.4480.4510.4420.445
9/160.5630.250BN056025S0.5050.5640.0480.05824047280.5110.5140.5050.508
15 mm0.5910.236BN15X6S0.5320.5920.0480.05827049300.5390.5420.5320.535
5/80.6250.250BN062025S0.5670.6270.0480.05830075380.5730.5760.5670.570
17 mm0.6690.472BN17X12S0.6110.6710.0480.058640185920.6170.6200.6110.614
11/160.6880.375BN068037S0.6290.6900.0480.058510160800.6360.6390.6290.632
3/40.7500.500BN075050S0.6720.7520.0660.0788802001200.6810.6840.6720.675
20 mm0.7870.472BN20X12S0.7100.7890.0660.0788401751100.7180.7210.7100.713
7/80.8750.500BN087050S0.7970.8770.0660.07810003001850.8060.8090.7970.800
15/160.9380.500BN093050S0.8590.9400.0660.07811254052450.8690.8690.8590.862
25 mm0.9840.472BN25X12S0.9070.9860.0660.07811002751700.9150.9180.9070.910
11.0000.500BN100050S0.9221.0020.0660.07812004002450.9310.9340.9220.925
1 1/81.1250.500BN112050S1.0471.1270.0660.07813005153151.0561.0591.0471.050
30 mm1.1810.512BN30X13S1.1041.1830.0660.07814005503401.1121.1151.1041.107
1 3/161.1880.875BN118087S1.1091.1900.0660.078250011507001.1191.1221.1091.112
1 1/41.2500.750BN125075S1.1721.2520.0660.07812007404501.1811.1841.1721.175
1 3/81.3750.688BN137068S1.2971.3770.0660.07811707704101.3051.3091.2971.301
35 mm1.3780.669BN35X17S1.3001.3800.0660.07812207854151.3081.3121.3001.304
1 1/21.5000.750BN150075S1.4221.5020.0660.078150011205951.4301.4341.4221.426
40mm1.5750.551BN40X14S1.4971.5770.0660.07812008504501.5051.5091.4971.501
1 5/81.6251.000BN162100S1.5471.6270.0660.078220018009551.5551.5591.5471.551
1 3/41.7501.000BN175100S1.6721.7520.0660.0782400210011151.6801.6841.6721.676
22.0001.000BN200100S1.9222.0020.0660.0782700290017751.9311.9341.9221.926

Case Study for BN Ring

Tolerance Ring Solution for Torque Transfer

Tolerance Rings can be used to transmit torque from one cylindrical component to another, without the need for costly splines or expensive keyways. Gears, pulleys, disks, sprockets, flywheels, rollers, impellers are a sample of the many torque transmitting components that can be mounted with tolerance rings. Unlike a keyway’s tolerances which result in backlash with a change in rotational direction, the tolerance ring provides zero backlash.

Depending on the diameter of the mounting components and the configuration of the tolerance ring, torques from .015 ft.-lbs. to 175 ft.-lbs. and much higher can be handled prior to slippage. The amount of torque transmitted will vary with tolerance ring configurations, diameters, material hardness, surface finish, and the amount of thermal expansion/contraction occurring between components. The slippage can provide natural torque overload protection, acting as a “fuse” and preventing damage to less sturdy components such as plastic gear teeth.

New Project Information Form

Please fill out as much information about your project below as possible. We may respond with further questions about your project’s specs, so please let us know who we should reply to.