When precision, reliability, and load-handling capacity matter, double row angular contact ball bearings are a preferred choice across industries. One standout in this category is the 3309A bearing, known for its durability and performance in both radial and axial load applications. In this guide, BYWB Bearing answers common questions and provides a comprehensive overview to help engineers, distributors, and procurement specialists make informed decisions.
3309A Bearing Specifications
The 3309A is a double row angular contact ball bearing manufactured with a steel cage, ideal for medium to high-load applications. Here are the detailed specifications:
| Parameter | Value |
| Bearing Number | 3309A |
| Designation | Double Row Angular Contact Ball Bearing |
| Inner Diameter (d) | 45 mm |
| Outer Diameter (D) | 100 mm |
| Width (B) | 39.7 mm |
| Contact Angle | 30° |
| Cage Material | Steel |
| Dynamic Load Rating | 62.2 kN |
| Static Load Rating | 38 kN |
| Limiting Speed (Grease) | ~7,000 RPM (manufacturer-specific) |
| Limiting Speed (Oil) | ~9,000 RPM (manufacturer-specific) |
| Manufacturer Equivalent | SKF, NSK, KOYO, FAG, BYWB |
At BYWB Bearing, we manufacture 3309A bearings with strict quality control, premium raw materials, and high-precision grinding to ensure exceptional performance and longevity.
What Size Is a 3309 Bearing?
The 3309 bearing, including type 3309A, has the following standard dimensions:
Bore diameter (d): 45 mm
Outer diameter (D): 100 mm
Width (B): 39.7 mm
This size makes it suitable for medium-duty applications where both axial and radial loads are present. The double-row design provides improved rigidity and load distribution compared to single-row bearings.
What Is the Difference Between 3309ZZ and 3309-2RS Bearings?
When comparing bearing suffixes like Z and 2RS, it’s essential to understand their functional differences:
| Type | Sealing / Shielding | Protection Type | Typical Use Case |
| 3309Z | One metal shield | Dust protection, no full seal | Applications with minimal contamination |
| 3309ZZ | Two metal shields | Both sides dust-protected | Moderate-speed applications |
| 3309-2RS | Two rubber seals | Fully sealed | Dirty, humid, or contaminated environments |
Key takeaway:
3309 ZZ: Two-side shielded (metal).
3309-2RS: Both sides sealed with rubber for better protection and grease retention.
At BYWB, we offer open, Z/ZZ, and 2RS variations to meet the demands of different environments.
What Is the 3309A Bearing Used For?
The 3309A bearing is widely used in applications requiring support for combined radial and axial loads. The 30° contact angle allows it to handle axial forces in both directions, making it a versatile choice in:
Electric motors
Gearboxes
Pumps and compressors
Agricultural machinery
Textile machines
Construction and mining equipment
Conveyor systems
Its double-row construction provides extra rigidity and stability under load, especially in high-speed or heavy-load applications.
Double Row Angular Contact Ball Bearing Size Chart
Here’s a quick size chart of common double row angular contact ball bearings for easy reference:
| Bearing | Boundary dimensions | Basic load ratings | Limiting speeds | Mass | ||||
| No. | mm | KN | RPM | KG | ||||
| d | D | B | dynamic Cr | static Cor | Grease | Oil | ||
| ZZ 2RS | open | |||||||
| 5200 | 10 | 30 | 14.3 | 6.95 | 3.8 | 14000 | 19000 | 0.049 |
| 5201 | 12 | 32 | 15.9 | 7.6 | 4.5 | 13000 | 17000 | 0.057 |
| 5202 | 15 | 35 | 15.9 | 8.2 | 5.25 | 11000 | 15000 | 0.064 |
| 5302 | 15 | 42 | 19 | 17.2 | 10.1 | 9900 | 13000 | 0.132 |
| 5203 | 17 | 40 | 17.5 | 10.8 | 7.1 | 9900 | 13000 | 0.096 |
| 5303 | 17 | 47 | 22.2 | 20.4 | 12.1 | 9000 | 12000 | 0.181 |
| 5204 | 20 | 47 | 20.6 | 15.8 | 10.1 | 8800 | 12000 | 0.153 |
| 5304 | 20 | 52 | 22.2 | 20.6 | 12.7 | 8000 | 11000 | 0.217 |
| 5205 | 25 | 52 | 20.6 | 18.2 | 13.2 | 7300 | 9800 | 0.175 |
| 5305 | 25 | 62 | 25.4 | 30.5 | 20.5 | 6700 | 8900 | 0.362 |
| 5206 | 30 | 62 | 23.8 | 26.1 | 19.7 | 6300 | 8400 | 0.286 |
| 5306 | 30 | 72 | 30.2 | 39.5 | 27.5 | 5700 | 7600 | 0.553 |
| 5406 | 30 | 90 | 39.7 | – | – | – | – | 0.14 |
| 5207 | 35 | 72 | 27 | 33 | 24.5 | 5500 | 7400 | 0.436 |
| 5307 | 35 | 80 | 34.9 | 49.5 | 35 | 5000 | 6600 | 0.766 |
| 5407 | 35 | 100 | 44.4 | – | – | – | – | 1.95 |
| 5208 | 40 | 80 | 30.2 | 40.5 | 32 | 4900 | 6600 | 0.59 |
| 5308 | 40 | 90 | 36.5 | 60.5 | 44 | 4400 | 5900 | 1.01 |
| 5408 | 40 | 110 | 49.2 | – | – | – | – | 2.55 |
| 5209 | 45 | 85 | 30.2 | 40 | 32.5 | 4400 | 5900 | 0.64 |
| 5309 | 45 | 100 | 39.7 | 72.5 | 54 | 4000 | 5300 | 1.34 |
| 5409 | 45 | 120 | 54 | – | – | – | – | 3.25 |
| 5210 | 50 | 90 | 30.2 | 39 | 35 | 4000 | 5300 | 0.689 |
| 5310 | 50 | 110 | 44.4 | 85.5 | 64.5 | 3600 | 4800 | 1.81 |
| 5410 | 50 | 130 | 58.7 | – | – | – | – | 4.1 |
| 5211 | 55 | 100 | 33.3 | 56 | 49 | 4300 | 5100 | 0.96 |
| 5311 | 55 | 120 | 49.2 | 106 | 82 | 3300 | 4400 | 2.32 |
| 5411 | 55 | 140 | 63.5 | – | – | – | – | 5.05 |
| 5212 | 60 | 110 | 36.5 | 74.4 | 60.8 | 3500 | 4700 | 1.4 |
| 5312 | 60 | 130 | 54 | 122 | 95.5 | 3000 | 4000 | 3.05 |
| 5412 | 60 | 150 | 68.3 | – | – | – | – | 6 |
| 5213 | 65 | 120 | 38.1 | 86.9 | 75.3 | 3200 | 4300 | 1.66 |
| 5313 | 65 | 140 | 58.7 | 138 | 109 | 2800 | 3700 | 3.96 |
| 5214 | 70 | 125 | 39.7 | 94.5 | 82.6 | 3100 | 4100 | 1.82 |
| 5314 | 70 | 150 | 63.5 | 155 | 125 | 2600 | 3500 | 4.74 |
| 5215 | 75 | 130 | 41.3 | 92.4 | 120 | 2900 | 3900 | 2.1 |
| 5315 | 75 | 160 | 68.3 | 168 | 141 | 2400 | 3200 | 5.65 |
Note: These values are typical. Contact BYWB Bearing for specific technical drawings and tolerances.
Conclusion
The 3309A double row angular contact ball bearing is a robust and reliable solution for applications requiring high load capacity and dual-direction axial support. With its precision steel cage and wide compatibility with global standards (SKF 3309A, FAG 3309A, etc.), it’s a versatile choice for engineers and OEMs alike.
At BYWB Bearing, we supply 3309A and other double row angular contact bearings with competitive pricing, strict QC, and fast lead times. Contact us today for technical datasheets, samples, or a customized quote.
