Four Point Contact Ball
Bearings
QJ series four point contact ball bearings feature a split inner ring and one-piece outer ring design, supporting bidirectional axial loads within a compact bearing arrangement.
QJ Series Bearing Structure
Split inner ring with one-piece outer ring for axial positioning.
Structural Design of Four Point Contact Ball Bearings
QJ series bearings are part of the angular contact ball bearings family. With a split inner ring and a one-piece outer ring, they are designed to locate axial loads in both directions while saving space in the bearing arrangement.
One-Piece Outer Ring
The one-piece outer ring keeps the raceways aligned and helps the bearing run steadily under axial load.
Split Inner Ring
The split inner ring forms the raceway shape needed for four-point contact, allowing the bearing to carry axial load from either direction.
Controlled Ball Contact
The balls contact the raceways at set angles, so axial force can be guided through the bearing in a controlled way.
How Four Point Contact Ball Bearings Carry Axial Loads
The gothic-arch raceway design gives each ball four possible contact points. In normal axial loading, one diagonal pair carries the load along the contact angle. If radial load is added, all four points may come into contact, which is why angular contact ball bearings in QJ design are mainly used for two-way axial location.
Standard Case — Pure Axial Load
Under pure axial load, the ball normally works on one diagonal pair of contact points. The load follows the X–X contact line, giving QJ series bearings compact two-way axial location with low friction.
Combined Axial & Radial Load
When radial load is added, the ball may contact all four raceway points. This can increase friction, heat, and wear, so a separate radial bearing is usually preferred for heavier radial load.
Engineering Tip: Four point contact ball bearings are best used for two-way axial location. If the arrangement must carry high radial load, it is better to use a separate radial bearing to reduce friction and heat.
Four Point Contact Ball Bearings vs Other Bearing Types
For arrangements that need axial location in both directions, engineers often compare deep groove ball bearings, paired angular contact bearings, and double row angular contact bearings. The best choice depends on axial load, radial load, available space, and stiffness requirements.
Deep Groove Ball Bearing
A common choice for radial load and moderate combined load. It can carry axial load in both directions, but axial capacity is limited compared with contact-angle bearing designs.
Four Point Contact Bearing
QJ series bearings are designed for two-way axial location in a compact space. In selected arrangements, one bearing can replace a paired angular contact bearing set.
Double Row Angular Contact
A rigid solution for combined radial and axial loads in both directions. It offers higher support stiffness, but usually needs more axial space.
QJ Series Four Point Contact Ball Bearing Size Chart
Use the table below to check QJ bearing dimensions, load ratings, fatigue load limit, and speed ratings. For special clearance, cage, or precision requirements, please contact TEDIN for confirmation.
Note: The table lists commonly supplied QJ series bearings. If your required designation is not shown, send us the bearing number or shaft size for checking.
Download PDF Catalogue| Designation | Principal Dimensions (mm) | Basic Load Ratings (kN) | Fatigue Load Limit (kN) | Speed Ratings (r/min) | ||||
|---|---|---|---|---|---|---|---|---|
| d | D | B | Dynamic C | Static C0 | Pu | Reference Speed | Limiting Speed | |
| QJ 324 N2MA | 120 | 260 | 55 | 415 | 530 | 16.3 | 3200 | 4500 |
| QJ 224 N2MA | 120 | 215 | 40 | 300 | 365 | 12 | 3600 | 5000 |
| QJ 326 N2MA | 130 | 280 | 58 | 455 | 610 | 18 | 3000 | 4000 |
| QJ 226 N2MA | 130 | 230 | 40 | 310 | 400 | 12.7 | 3400 | 4800 |
| QJ 228 N2MA | 140 | 250 | 42 | 345 | 475 | 14.3 | 3200 | 4300 |
| QJ 328 N2MA | 140 | 300 | 62 | 500 | 695 | 20 | 2800 | 3800 |
| QJ 230 N2MA | 150 | 270 | 45 | 400 | 570 | 16.6 | 3000 | 4000 |
| QJ 330 N2MA | 150 | 320 | 65 | 530 | 765 | 21.2 | 2600 | 3600 |
| QJ 1030 N2MA | 150 | 225 | 35 | 242 | 335 | 10.4 | 2800 | 4500 |
| QJ 332 N2MA | 160 | 340 | 68 | 570 | 880 | 23.6 | 2400 | 3400 |
| QJ 232 N2MA | 160 | 290 | 48 | 450 | 670 | 19 | 2800 | 3800 |
| QJ 1032 N2MA | 160 | 240 | 38 | 270 | 380 | 11.4 | 2600 | 4300 |
| QJ 334 N2MA | 170 | 360 | 72 | 655 | 1040 | 27 | 2200 | 3200 |
| QJ 234 N2MA | 170 | 310 | 52 | 455 | 720 | 20 | 2600 | 3400 |
| QJ 236 N2MA | 180 | 320 | 52 | 475 | 765 | 20.8 | 2400 | 3400 |
| QJ 336 N2MA | 180 | 380 | 75 | 680 | 1100 | 28 | 2200 | 3000 |
| QJ 338 N2MA | 190 | 400 | 78 | 702 | 1160 | 28.5 | 1700 | 2800 |
| QJ 238 N2MA | 190 | 340 | 55 | 510 | 850 | 22.4 | 2200 | 3200 |
| QJ 1038 N2MA | 190 | 290 | 46 | 364 | 560 | 15.3 | 2200 | 3400 |
| QJ 1040 N2MA | 200 | 310 | 51 | 390 | 620 | 16.6 | 2000 | 3200 |
| QJ 240 N2MA | 200 | 360 | 58 | 540 | 915 | 23.2 | 1800 | 3000 |
| QJ 1240 N2MA | 200 | 360 | 70 | 520 | 865 | 21.6 | 1800 | 3000 |
| QJ 344 N2MA | 220 | 460 | 88 | 780 | 1400 | 32 | 1500 | 2400 |
| QJ 1244 N2MA | 220 | 400 | 78 | 364 | 1020 | 24.5 | 1800 | 1800 |
| QJ 344 N2/309829 | 220 | 460 | 88 | 904 | 1660 | 38 | 1500 | 2400 |
| QJ 1248 MA/344524 | 240 | 440 | 85 | 663 | 1220 | 28 | 1500 | 2400 |
| QJ 248 N2MA | 240 | 440 | 72 | 650 | 1200 | 27.5 | 1500 | 2400 |
| QJ 1252 MA | 260 | 480 | 90 | 741 | 1460 | 32 | 1300 | 2200 |
| QJ 252 N2MA | 260 | 480 | 80 | 728 | 1430 | 32 | 1300 | 2200 |
| QJ 1252 N2MA | 260 | 480 | 90 | 741 | 1460 | 32 | 1300 | 2200 |
How to Select QJ Series Four Point Contact Ball Bearings
Selecting the right QJ series bearing depends on axial load direction, radial load condition, mounting space, speed requirement, cage design, internal clearance, and operating environment.
Selection Principles for QJ Bearings
QJ series four point contact ball bearings are designed to support axial loads in both directions while occupying less axial space than a matched pair of angular contact ball bearings.
They are often used where compact design and bidirectional axial location are required. If radial load is significant, a separate radial bearing should be considered to reduce friction, heat, and wear.
Axial Load Direction
Choose QJ series bearings when axial loads may act in both directions and a compact axial locating arrangement is required.
Radial Load Condition
QJ bearings can accommodate limited radial load. For higher radial load, use a separate radial bearing to reduce friction, heat, and wear.
Bearing Dimensions
Match bore diameter, outside diameter, and bearing width with the shaft, housing, and available installation space.
Speed Requirement
Compare the required operating speed with the reference speed and limiting speed listed in the catalogue table.
Cage and Suffix
Suffixes such as MA, N2MA, and C4 may indicate cage design, locating features, or internal clearance. Confirm suffix details before ordering.
Clearance & Mounting
Internal clearance, shaft fit, housing fit, and mounting accuracy directly affect bearing temperature, noise, and service life.
Need help selecting a QJ bearing? Please provide bearing designation, shaft diameter, housing size, load direction, speed, lubrication method, and operating temperature. TEDIN can help review the suitable QJ series model or customized bearing solution.
Send Bearing RequirementsQJ Series Bearing Suffix Explanation
Common QJ series suffixes describe cage design, locating slots, internal clearance, or customized bearing variants.
| Suffix | Meaning | Application Notes |
|---|---|---|
| MA | Machined brass cage for higher cage strength and stable operation. | Used in heavy-duty conditions or applications requiring robust cage performance. |
| N2 | Two locating slots in one side face of the outer ring. | Helps position the outer ring or prevent rotation in the housing. |
| N2MA | Combined suffix for two locating slots and a machined brass cage. | Common QJ configuration for outer ring positioning and strong cage design. |
| C3 / C4 | Internal clearance greater than normal clearance. | Used with tighter fits, higher operating temperature, or additional running clearance. |
| Customized / Non-standard | Manufacturer-specific or customized bearing design. | May include special cage, clearance, heat treatment, precision class, or drawings. |
Important: Suffix definitions may vary between manufacturers. For replacement bearings, confirm dimensions, cage type, clearance, and application conditions before ordering.
Confirm Bearing SuffixQJ Series Four Point Contact Ball Bearing Applications
QJ series bearings are used in compact arrangements that require two-way axial location. They can accommodate limited radial load, while heavy radial loads should normally be supported by a separate radial bearing.
Machine Tool Rotary Tables
Compact two-way axial location for selected rotary and indexing arrangements.
Gearboxes
Used for axial location where gear forces generate thrust in both directions.
Pumps & Compressors
Helps locate shafts under changing axial thrust in rotating equipment.
Heavy Machinery
Supports compact axial locating arrangements in demanding industrial equipment.
Frequently Asked Questions About QJ Series Bearings
Short answers to common purchasing, replacement, and selection questions for QJ series four point contact ball bearings.
What is a QJ series four point contact ball bearing?
A QJ series bearing is designed for two-way axial location in a compact space. It can accommodate limited radial load, but heavy radial load should normally be supported by a separate radial bearing.
Can QJ bearings support axial loads in both directions?
Yes. QJ bearings can support axial loads from both directions and are often used where one bearing is required to locate the shaft axially in a compact arrangement.
What does N2MA mean in QJ bearings?
N2 usually indicates two locating slots on the outer ring, while MA indicates a machined brass cage. Suffix meanings should be confirmed when replacing bearings from different brands.
How do I choose the right QJ bearing size?
Selection depends on shaft size, housing size, load direction, speed, lubrication, clearance, and operating conditions. For replacement, the full designation and photos are helpful.
Can TEDIN supply customized QJ series bearings?
Yes. TEDIN can supply standard and customized QJ series bearings according to bearing designation, drawings, samples, cage type, clearance, locating features, or special application requirements.
Need help with QJ bearing selection? Send us the bearing designation, drawings, photos, or operating conditions, and TEDIN can help review the suitable QJ series bearing solution.
Send QJ Bearing Requirements
Need a QJ Series Bearing for Your Application?
Send us the bearing designation, drawings, photos, or operating conditions. TEDIN can help review the suitable QJ series four point contact ball bearing for axial location, replacement, or customized requirements.
Model number, drawings, sample photos, load and speed details are helpful.