For HUB 1, NSK uses proprietary bearing-type designations such as "BWD" for ball bearings and "KWD" for tapered roller bearings. The HUB 1 NSK wheel bearings units are double-row angular contact ball bearings (BWD) and double-row tapered roller bearings (KWD) with back-to-back duplex outer rings.
No preload a djustments (including dimensional adjustments by shims) are required on the assembly line. The initial axial clearance is properly pre-set for the preload to fall within the specified range after mounting. In addition, the integral seal eliminates the need for automotive makers to externally apply seals.
NSK uses bearing reference for hub unit bearings clarifying boundary dimensions, types, and specification codes. Below are examples of NSK bearing reference:
For example: 35 BWD 18
- 35: bore diameter 35mm
- BWD: HUB 1 ball bearings
- 18: Serial No.

related articles
- NSK wheel bearing selection
- NSK wheel bearing types selection
- Fit and preload of NSK wheel bearings
- Material for NSK wheel bearings
Related numbers

NSK 38KWD02 bearing
38mm x 68mm x 37mm

NSK 45KWD03 bearing
45mm x 78mm x 37mm

NSK 28BWD01A bearing
28mm x 61mm x 42mm

NSK 32BWD05 bearing
32mm x 72mm x 45mm

NSK 36BWD01B bearing
36mm x 72.041mm x 34mm

NSK 38BWD12 bearing
38mm x 72mm x 33mm

NSK 40BWD12 bearing
40mm x 74mm x 42mm
