Products

Four Point Contact Bearings

Product Overview

Four Point Contact Bearings are a single-row ball bearing type featuring specially profiled raceway grooves on both inner and outer rings, designed such that each ball makes contact with the raceways at four distinct points (two on each ring) under load. This unique geometry allows a single-row bearing to support radial loads, axial loads in both directions, and tilting moment loads simultaneously, effectively replacing what would otherwise require a paired angular contact bearing arrangement.

The inner and/or outer ring is typically split (two-piece) construction, allowing a full complement of balls to be assembled for maximum load capacity, or a caged design for higher speed capability. Precision grades range from standard to high precision, and sealing options include open type and contact seals (RS/2RS) depending on application requirements.

Technical Specifications

Series	QJ2, QJ3 Series
Bore Diameter Range	10mm – 500mm
Outer Diameter Range	30mm – 870mm
Width Range	9mm – 200mm
Cage Material Options	Steel stamped, machined brass, polyamide PA66
Ring Structure Options	Split inner ring (full complement), one-piece ring with cage
Precision Grades	P0 standard, P6 high precision
Radial Clearance	CN normal, C3, C4 increased
Material Standard	Gcr15 / 52100 chrome steel, stainless steel SS440
Temperature Range	-30°C to +150°C standard, up to +200°C high temperature
Lubrication	Grease standard, oil optional
Standards Met	ISO 9001, ISO 15, DIN 628

Key Features

Bidirectional axial and moment load capacity in a single row – eliminates the need for paired bearing arrangements in many applications, reducing axial installation space
Compact axial footprint – supports combined loading within a single-row width, comparable to or narrower than paired angular contact configurations
Split-ring design options – allows full-complement ball loading for higher capacity, or caged designs for higher speed operation
High rigidity under combined loading – well-suited for applications involving simultaneous radial, axial, and tilting moment loads
Compatible with grease and oil lubrication, suitable for standard industrial and precision rotary applications
Compliant with relevant ISO and DIN dimensional standards for slewing and four-point contact bearing series

Applications

Four Point Contact Bearings are widely used in robotics and rotary table applications, where compact axial space combined with the need to resist tilting moments makes this bearing type particularly effective.

In construction and material handling equipment, including crane slewing rings and excavator turntables, the series supports the combined radial, axial, and moment loading generated during rotation and load handling.

In machine tool rotary axes and indexing tables, Four Point Contact Bearings provide the rigidity and moment resistance required for precise rotational positioning under varying load conditions.

The series is also applied in medical imaging equipment, packaging machinery, and other rotary platforms, wherever combined load support within a compact single-row envelope is required.

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.

Four Point Contact 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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