Products

Needle Roller Bearings

Product Overview

Needle Roller Bearings are a compact rolling bearing type utilizing long, thin cylindrical rollers (needle rollers) with a small diameter-to-length ratio, arranged radially around the shaft. This design provides high radial load capacity within an extremely small cross-sectional envelope, making needle roller bearings the preferred choice for applications where radial space is severely limited but load support requirements remain substantial.

Available in multiple configurations – including needle roller bearings with cage (drawn cup or machined ring type), without inner ring, full complement (without cage), and combined needle/thrust types – the series can be tailored to specific shaft, housing, and load requirements. Precision grades typically range from standard to high precision, and most variants accommodate either grease or oil lubrication. Sealing options include open type and sealed (with integrated seal lips) configurations for contamination protection in compact assemblies.

Technical Specifications

Series	NA, NK, RNA (with inner ring), HK, BK (without inner ring, drawn cup)
Bore Diameter Range	3mm – 200mm
Outer Diameter Range	7mm – 250mm
Width Range	4mm – 70mm
Cage Material Options	Steel stamped, polyamide PA66
Structural Options	With/without inner ring, with cage, full complement
Precision Grades	P0 standard, P6 high precision
Radial Clearance	CN normal, C3 increased
Material Standard	Gcr15 / 52100 chrome steel, case-hardened carbon steel
Temperature Range	-40°C to +120°C standard, up to +150°C high temperature
Lubrication	Grease standard, oil optional
Standards Met	ISO 9001, ISO 3245, DIN 617/618, JIS

Key Features

High radial load capacity in minimal cross-section – the long, thin roller geometry maximizes the contact length-to-diameter ratio, optimizing load capacity for a given outer diameter
Compact and lightweight design – significantly reduces radial space requirements compared to ball or standard cylindrical roller bearings of equivalent load capacity
Multiple structural variants – available with or without inner ring, with cage or full complement rollers, to match cost, load, and space requirements
Combined bearing options – needle roller/thrust ball or needle roller/angular contact combinations available for simultaneous radial and axial load support
Compatible with grease and oil lubrication, suitable for both standard industrial and high-load automotive applications
Compliant with international standards, including ISO 3245, DIN 617/618, and JIS

Applications

Needle Roller Bearings are extensively used in the automotive industry, including transmissions, rocker arm pivots, universal joints, and connecting rod assemblies, where radial space constraints and high load demands coexist.

In industrial gearboxes and power tools, the series provides high load capacity within compact housing designs, supporting shafts subject to continuous radial loading.

In construction and agricultural machinery, needle roller bearings support pivot points, linkages, and compact drive components requiring reliable performance under heavy and variable loads.

The series is also widely applied in textile machinery, printing equipment, and general industrial mechanisms, wherever compact radial support is required without compromising load-carrying capability.

Electric Tools

Automotive

Machine Tools

Agriculture Machinery

Food and Beverage

Robotics

Technical Resources

Whether you are an engineer, procurement manager, or equipment maintenance professional, here you will find in-depth content covering bearing operating principles, technical parameter interpretation, industry application analysis, and selection logic — helping you build a comprehensive understanding of bearing products and make more informed decisions in real-world applications.

Needle Roller Bearings A Complete Guide to Structure, Working Principle, Selection, and Applications

Bearing Seals and Shields: A Complete Guide to Z, ZZ, RS, RZ, RS1, and 2RS1 Types

Select Bearing Metal Materials: Common Standards and Purchasing Guidelines Bearing Metal Materials: Common Standards and Purchasing Guidelines

Selection Guide for Deep Groove Ball Bearing Clearance: C3 vs. C0 (CN)

FAQs

What loads can deep groove ball bearings handle?

Deep groove ball bearings are primarily designed for radial loads, but they can also handle moderate axial (thrust) loads in both directions. They are not suitable for heavy axial loads or combined shock loads. In those cases, angular contact or tapered roller bearings are preferred.

How do I select the right bearing size for my application?

Selection should be based on bore diameter (shaft size), required load capacity (dynamic rating C and static rating C0), operating speed compared with the bearing limiting speed, available space (outer diameter and width), and required precision grade from P0 to P2. Always apply a safety factor and verify that the calculated L10 service life meets your requirements.

What is the difference between open, shielded (ZZ), and sealed (2RS) bearings?

Open: No built-in protection, requires external sealing, and is suitable for clean environments or oil bath lubrication.

ZZ metal shields: Protect against dust and debris with low friction, making them suitable for high-speed applications, but they are not waterproof.

2RS rubber seals: Provide strong protection against dust and moisture. They are pre-greased and ideal for contaminated environments, but generate slightly more friction.

How often should I lubricate or replace the grease?

For general industrial use, grease should be replenished or replaced every 3,000 to 10,000 operating hours depending on speed, temperature, and environmental conditions. Bearings running above 70 C or in contaminated environments require shorter intervals. Sealed 2RS bearings are pre-greased for life and do not require re-lubrication.

What are the common causes of premature bearing failure?

The most frequent causes include inadequate or improper lubrication, contamination by dirt, dust, or moisture, incorrect installation, misalignment, excessive force during fitting, overloading beyond the rated capacity, improper shaft or housing fits, and fatigue at the end of normal service life.

How is the rated service life (L10) of a bearing calculated?

The basic L10 life is calculated as L10 = (C / P)^3 x 10^6 revolutions, where C is the dynamic load rating in kN and P is the equivalent dynamic bearing load in kN. It represents the number of revolutions that 90% of identical bearings will complete without fatigue failure. In practice, ISO 281 modified life calculations also apply correction factors for lubrication, contamination, material, and reliability.

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