NJ cylindrical roller bearings are specifically engineered to accommodate heavy radial loads while providing axial shaft location in one direction. Featuring an outer ring with two integral ribs and an inner ring with a single rib, this bearing design offers excellent rigidity while allowing thermal expansion of the shaft in the opposite direction. Thanks to these characteristics, NJ bearings are widely used in electric motors, gearboxes, conveyor rollers, and other industrial equipment requiring precise shaft positioning and reliable long-term performance. If you're looking for genuine NJ cylindrical roller bearings at competitive prices, Belota supplies a comprehensive range of models from leading brands including SKF, NSK, NTN, and FAG, backed by professional technical support.
What Are NJ Cylindrical Roller Bearings?
NJ cylindrical roller bearings are separable rolling bearings specifically designed for applications requiring high radial load capacity together with axial shaft location in one direction.
The bearing consists of the following key components:
- Outer Ring: Features two integral ribs (flanges) that retain the roller and cage assembly.
- Inner Ring: Designed with a single integral rib on one side, while the opposite side remains open.
This configuration is common among several types of cylindrical roller bearings, but the NJ design is optimized to combine excellent radial load capacity with one-direction axial shaft location.
Its unique flange arrangement creates a single-direction locating function, preventing shaft movement toward the ribbed side while allowing unrestricted thermal expansion in the opposite direction.
Key Technical Features
To select and apply NJ cylindrical roller bearings correctly, it is important to understand their three primary performance characteristics.
Superior Radial Load Capacity
Thanks to the line contact between the cylindrical rollers and raceways, NJ bearings can support significantly higher radial loads than deep groove ball bearings of the same size. This makes them highly suitable for applications exposed to heavy loads, impact forces, and continuous vibration.
One-Direction Axial Load Capacity
Unlike NU cylindrical roller bearings, NJ bearings can accommodate limited axial loads in one direction. Typically, the permissible axial load is approximately 10–20% of the radial load capacity, achieved through sliding contact between the roller end faces and the locating flange of the inner ring.
Semi-Locating Bearing Function
In gearboxes, electric motors, and other rotating machinery, NJ bearings commonly serve as the locating bearing.
They prevent axial shaft movement in one direction while allowing thermal expansion in the opposite direction, helping maintain proper shaft alignment during operation.
Important Installation Note
Because NJ bearings locate the shaft in only one direction, the bearing must be installed with the locating flange facing the expected axial load.
Incorrect installation will eliminate the locating function and may lead to premature bearing failure.
NJ Cylindrical Roller Bearing Dimensions (Popular Models)
NJ cylindrical roller bearings are manufactured according to international ISO dimensional standards. Below are several commonly used bearing sizes.
| Bearing Model | Bore (d) | Outside Diameter (D) | Width (B) | Dynamic Load Rating C (kN) |
|---|---|---|---|---|
| NJ 205 | 25 mm | 52 mm | 15 mm | 29 |
| NJ 206 | 30 mm | 62 mm | 16 mm | 40 |
| NJ 208 | 40 mm | 80 mm | 18 mm | 58 |
| NJ 210 | 50 mm | 90 mm | 20 mm | 72 |
| NJ 306 | 30 mm | 72 mm | 19 mm | 56 |
| NJ 308 | 40 mm | 90 mm | 23 mm | 88 |
| NJ 310 | 50 mm | 110 mm | 27 mm | 115 |
| NJ 2210 | 50 mm | 90 mm | 23 mm | 85 (Double-row type) |
Note: Suffixes such as ECP, M, and C3 indicate cage material, internal clearance, and other bearing specifications.
Cage Material Options
NJ cylindrical roller bearings are available with different cage materials to suit various operating conditions and rotational speeds.
Pressed Steel Cage (Suffix J)
The standard and most economical option, suitable for medium-duty applications under normal operating conditions.
Machined Brass Cage (Suffix M)
Manufactured from solid brass, this cage provides superior mechanical strength and excellent resistance to heavy shock loads. It is commonly used in mining equipment, stone crushers, heavy-duty gearboxes, and other demanding industrial applications.
Polyamide Cage (Suffix P / TVP / ECP)
Constructed from reinforced polyamide, this lightweight cage reduces friction and operating noise while supporting high rotational speeds. However, its recommended operating temperature is generally limited to 120°C.
Where to Buy Genuine NJ Cylindrical Roller Bearings?
Selecting the correct NJ bearing model and installing it in the proper axial direction are essential for maximizing bearing life and ensuring reliable machine performance. Even a minor installation error involving the locating flange can result in premature equipment failure and costly downtime.
If you're looking for a reliable bearing supplier with strong technical expertise, Belota is your trusted partner.
Why Choose Belota?
- Professional technical support to help identify the correct bearing model and installation orientation.
- 100% genuine products supplied with complete CO/CQ documentation from leading brands including SKF, NSK, FAG, and NTN.
- Flexible return policy for incorrectly ordered products (unused condition).
- Competitive pricing with attractive discounts for factories, OEMs, and industrial projects.
Contact Belota today via Hotline/Zalo: +84 917 657 946 for expert technical consultation and a fast quotation.
