Industrial Ball Bearing NTN 6903 JRXLLUC3/5K 17x30x7 - Precision, Reliability & High-Demand Performance

Applications

The NTN 6903 JRXLLUC3/5K is a high-performance deep groove ball bearing engineered for precision applications where low friction, high speed and reliability are essential. With compact dimensions of 17x30x7 mm, it is widely used in electric motors, pumps, gearboxes, conveyors, automation systems, and machine tools.
Thanks to its LLU double-rubber seal, it offers excellent protection against dust, moisture and contaminants, extending bearing life and reducing downtime in demanding industrial environments.

Advantages

• Japanese engineering excellence (NTN) - ensures perfect geometry, quiet operation and long service life.

• Sealed on both sides (LLU) - prevents grease leakage and contamination, making the bearing maintenance-free.

• C3 internal clearance - allows for higher operating speeds and thermal stability in continuous-duty machinery.

• High durability - made from premium bearing steel, resistant to wear, vibration and temperature fluctuations.

• Compact design (17x30x7 mm) - ideal for tight installations requiring precision and smooth motion.

Technical Data

• Type: Deep groove ball bearing, single row

• Manufacturer: NTN (Japan)

• Dimensions: 17 mm (ID) x 30 mm (OD) x 7 mm (Width)

• Sealing: LLU - double rubber seals

• Internal Clearance: C3 (increased, for high-speed operation)

• Cage: Steel, riveted

• Dynamic load rating: 5.15 kN (approx.)

• Static load rating: 2.58 kN (approx.)

• Speed limit (grease lubrication): up to 14 000 rpm

• Operating temperature: -25 °C to +110 °C

• Lubrication: Factory-filled high-performance grease

• Typical applications: motors, pumps, precision gearboxes, automation, conveyors, power tools

FAQ

1. What does the code JRXLLUC3/5K mean?
It specifies a particular NTN internal design: JR (cage type), X (manufacturing specification), LLU (double rubber seals), C3 (increased clearance for high speed), and 5K (production variant for consistent performance).

2. What are the benefits of LLU seals?
LLU double-rubber seals provide superior protection against contaminants and moisture, helping to retain lubricant inside the bearing and extending its operational life.

3. When should I choose C3 clearance?
C3 clearance is recommended for bearings operating at higher speeds or under elevated temperatures, as it compensates for thermal expansion and ensures smooth operation.

4. Is this bearing interchangeable with 6903 2RS?
Yes, the NTN 6903 JRXLLUC3/5K can replace standard 6903 2RS bearings, offering enhanced sealing, superior material quality and longer lifespan.

5. What industries use this bearing size?
It is widely used in automation, robotics, electric motor manufacturing, machine tools, automotive assemblies, and industrial transmission systems.