• Model / Part Number: 6203-2RS (6203 2RS / 6203-2RU / C3 Radial Clearance)
• Bearing Type: Single Row Deep Groove Radial Ball Bearing
• Seal Type: 2RS Contact Sealed Both Sides with Synthetic Rubber
• Size: 17 mm Bore x 40 mm Outer Diameter x 12 mm Width (17x40x12 mm)
• Minimum Chamfer Dimension: 0.6 mm
• Dynamic Load Rating (Cr): 12.0 kN
• Static Load Rating (Cor): 4.80 kN
• Fatigue Load Limit (Cu): 0.370 kN
• Limiting Speed: 12,000 RPM (Grease Lubrication)
• Lubrication: Factory Pre-Lubricated with High-Performance Grease
• Reference Weight: Approx. 65 g per bearing

The authentic KOYO 6203-2RS Bearing is precision engineered by JTEKT Corporation to deliver smooth rotational stability, reduced mechanical friction, and continuous running endurance across demanding rotary equipment. Featuring an optimized single-row deep groove raceway geometry and precision-matched hardened steel balls, this bearing efficiently carries dynamic radial loads and bidirectional axial forces with minimal heat generation, quiet running performance, and low vibration output.

Equipped with dual contact rubber seals on both faces, this KOYO 6203-2RS Bearing ensures that internal factory-applied lubricating grease remains securely trapped inside while locking out abrasive dust, moisture, and road grit. Designed to standard metric dimensions of 17x40x12 mm, it serves as a seamless direct-fit replacement component for automotive alternators, motorcycle wheel hubs, electric motors, water pumps, power tools, and lawn equipment.

- Dual Contact Rubber Seals: Blocks external contamination and locks in grease, giving each KOYO 6203-2RS Bearing extended service life.
- Pre-Lubricated for Ready Use: Packed at the factory with premium grease to allow immediate installation with zero initial maintenance.
- High-Speed Precision Performance: Balanced rolling elements provide smooth, quiet running with grease-lubricated limiting speeds up to 12,000 RPM.
- Robust Load Capacity: Rated for 12.0 kN dynamic load and 4.80 kN static load to withstand demanding operational mechanical stress.
- Standard Metric Dimensions: Precision 17x40x12 mm fitment ensures broad compatibility across diverse automotive, industrial, and power tool machinery.

• Bearing Rings: High-carbon chromium bearing steel (SUJ2 / 52100) inner and outer raceways provide outstanding contact fatigue endurance for the KOYO 6203-2RS Bearing.
• Rolling Elements: High-precision spherical steel balls deliver balanced load transmission, low friction, and minimal vibration.
• Retaining Cage: Pressed sheet steel cage maintains uniform ball spacing and stable guidance during high-speed rotation.
• Contact Seals: Nitrile butadiene rubber (NBR) with integrated steel reinforcement creates a firm, protective barrier against external debris.
• Internal Lubricant: Mineral-based lithium grease ensures continuous friction reduction and operational protection.

1. Confirm that the 6203-2RS designation and 17x40x12 mm dimensions match your equipment specifications.
2. Clean and inspect the shaft journal and housing bore thoroughly to remove old grease, rust, or metal shavings.
3. Keep the bearing sealed in its original protective packaging until the moment of installation.
4. Press the bearing squarely into position using a proper mechanical bearing driver tool or arbor press.
5. Apply mounting pressure strictly to the press-fit ring, never transferring force through the rolling balls or rubber seals.
6. Check for smooth, unrestricted manual rotation before returning the assembled machine to active service.

High-Carbon Chromium Bearing Steel (SUJ2 / AISI 52100), Precision Steel Balls, Pressed Sheet Steel, Nitrile Butadiene Rubber (NBR) with Steel Reinforcement, Mineral Oil-Based Lithium Grease