Four-Point Contact Angular Contact Ball Bearings (General)
Four-point contact angular contact ball bearings are QJ series bearings designed to support radial load together with axial load in both directions within a single-row bearing structure. This product list covers metric 4 point contact ball bearing options from 15 mm to 480 mm bore, including QJ 20, QJ 30, QJ 21, QJ 31 and large QJ 10/QJ 12 series models. Buyers can compare bore size, outer diameter, width, pressure point distance, open design, brass or PEEK cage, P6 tolerance, load rating and speed. TFL helps customers source suitable QJ bearing replacements or alternatives based on part number, drawing, sample or application requirements.
Handles Bi-Directional Axial & Radial Loads
Significant Axial Space Saving
Simplified Application Design
Four Point Contact Bearing Selection Guide
Four point contact bearings are QJ series angular contact ball bearings used when one bearing position must support axial load in both directions together with a limited radial load. They are often selected to save axial space compared with using two single row angular contact bearings in a paired arrangement.
How to Choose This Bearing Type
Choose a four point angular contact ball bearing when the application has reversing axial load, limited axial space, or a locating bearing position that needs axial support in both directions. It is suitable for combined-load applications, but radial load should not be the only selection factor. Confirm the axial load direction, radial load level, shaft arrangement, lubrication method, and installation space before choosing from the product list.
How to Read QJ Four Point Contact Bearing Numbers
QJ bearing numbers usually describe the four point contact structure, size series, bore code and cage or design suffix. For example, in QJ 208 N2MA, “QJ” indicates a four point contact angular contact ball bearing, “2” refers to the dimensional series, and “08” is the bore code, which equals 40 mm for standard metric bearing numbering. The suffix “N2MA” should be checked carefully because it may relate to locating features and cage design depending on the original brand-style number.
| Code Element | What It Usually Means | Why It Matters for Replacement |
|---|---|---|
| QJ | Four point contact angular contact ball bearing | Confirms the bearing is for bidirectional axial load support, not a standard single row angular contact bearing. |
| 2, 3, 10, 12 series | Dimensional series and bearing section | Affects width, load rating, stiffness and housing space. |
| 08, 10, 12, etc. | Bore code; for 04 and above, multiply by 5 mm | Example: 08 = 40 mm bore, 10 = 50 mm bore, 12 = 60 mm bore. |
| MA | Common brass cage suffix in this product range | Cage material can affect speed, temperature and replacement suitability. |
| N2MA | Brand-style suffix often related to locating features plus brass cage | Do not replace by size only; confirm suffix and drawing details before ordering. |
| PHAS / N2PHAS | PEEK cage option in this product list | Useful when cage material, speed or operating conditions are important. |
Common Series and Model Range
| Series / Model Type | Typical Range on This Page | Selection Notes |
|---|---|---|
| QJ 20 / QJ 30 series | Common medium-size QJ models | Useful for gearboxes, pumps, compressors, and industrial drive assemblies. |
| QJ 21 / QJ 31 series | Wider bearing sections and higher load options | Check width, contact geometry, and housing space carefully. |
| QJ 10 / QJ 12 large-size series | Large bore models for heavy equipment | Suitable for heavy rotating equipment where axial location and bearing stiffness matter. |
Open QJ Design, Cage, and Suffix Selection
The models on this page are open four point contact bearings, so lubrication, cleanliness, and mounting environment should be confirmed before ordering. MA and N2MA models should be checked against the full product designation, while PHAS and N2PHAS models should also be confirmed against the full designation before assuming any cage or design detail. If your original bearing uses a specific brand-style suffix, send the full part number so we can check the closest interchange option.
Key Specifications to Confirm Before Quotation
For an accurate quotation, confirm the QJ bearing number, bore diameter, outer diameter, width, cage material, contact geometry, dynamic and static load rating, maximum speed, tolerance class, lubrication requirement, and operating temperature. If you are replacing an existing bearing, photos of the bearing marking and drawings of the shaft and housing are also helpful.
SKF / FAG / NSK Replacement Notes
Many buyers search by SKF-style, FAG-style, or NSK-style QJ numbers when looking for four point contact bearing replacements. TFL can help compare QJ part numbers, dimensions, suffixes, and application requirements before recommending an alternative. We do not imply original-brand supply or authorized distribution; the goal is to help customers source suitable interchangeable bearings for the same installation position.
Common Applications
Four point contact angular contact ball bearings are commonly used in industrial gearboxes, pumps, compressors, vertical shaft equipment, crane mechanisms, slewing-related assemblies, wind power equipment, machine tools, and heavy machinery where bidirectional axial load support and compact axial space are important.
Popular Models / High-Demand Models
Common models in this range include QJ 304 N2MA, QJ 306 N2MA, QJ 208 N2MA, QJ 210 MA, QJ 212 N2MA, QJ 312 PHAS, and QJ 315 N2MA. For a priority model page, QJ 208 N2MA is a strong option because it represents a common QJ bearing size with a brass-cage variant and clear four point contact positioning.
Engineering Note
Four point contact bearings are not simply “stronger angular contact bearings.” Their value is bidirectional axial load support in limited axial space. If the application has mainly radial load or requires high moment stiffness, another angular contact arrangement may be more suitable.
Need Help Matching a QJ Four Point Contact Bearing?
Send us the bearing number, drawing, sample photos, or working conditions. TFL can help check dimensions, suffix interchange, cage material, load rating, and available sourcing options before shipment coordination.
TFL / SDTFL Bearing is a bearing supplier and sourcing partner. We help customers source suitable standard or customized bearing alternatives from qualified factory resources and inspect model, quantity, appearance, packaging, and basic quality requirements before shipment.
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