English
French
German
603 Deep Groove Ball Bearing 3x9x5mm
The 603 bearing is the smallest-bore standard deep groove ball bearing in the metric series. With a 3mm shaft diameter, 9mm outside diameter, and 5mm width, the 603 bearing fits assemblies where both radial space and shaft diameter are tightly constrained. Despite the compact 3x9x5mm envelope, the deep groove geometry delivers 0.15kN dynamic load capacity and spins to 59,000 RPM in the open configuration. Supplied in three configurations to match the operating environment: Open for housing-lubricated assemblies, ZZ for non-contact metal shields in dry environments, and 2RS for contact rubber seals where moisture or fine dust is present. All three share identical ring geometry, GCr15 chrome steel material, and ABEC-3 precision.
Key Specifications
- Dimensions: 3mm bore (d) x 9mm outside diameter (D) x 5mm width (B)
- Configuration: Available in Open, ZZ (metal-shielded), and 2RS (rubber-sealed)
- Load Ratings: 0.15kN dynamic (Cr), 0.219kN static (C0r)
- Speed Ratings: 59,000 RPM (Open / ZZ), 47,000 RPM (2RS)
- Material and Precision: GCr15 chrome steel (AISI 52100 equivalent), stamped steel cage, lithium grease, ABEC-3 tolerance
For any inquiries, please contact with our Supporting Team at sales@yuanhecd.com.
| Model | 603 |
| Type | Open / Shielded / Sealed |
| Bore Dia (d) | 3 mm |
| Outside Dia (D) | 9 mm |
| Width (B) | 5 mm |
| ABEC Tolerance | ABEC-3 |
| Dynamic Load Capacity (kN) | 0.23 kN |
| Static Load Capacity (kN) | 0.219 kN |
| Max. RPM | 59,000 RPM (Open/ZZ) / 47,000 RPM (2RS) |
| Temp. Range (℃) | -40~120℃ |
| Material | GCr15 (AISI 52100) |
| Shield/Seal | SPCC (ZZ) / NBR+SPCC (2RS) |
| Lubrication | Grease |
Bore (d)
3 mm
OD (D)
9 mm
Width (B)
5 mm
Dyn. Load
0.23 kN
Max RPM
59,000
Precision
ABEC-3
Configuration Options
The 603 bearing is supplied in three configurations. All share identical ring and ball geometry, so load ratings and ABEC-3 precision remain the same regardless of shield or seal choice.
Open 603 bearing carries no shields or seals, reaching 59,000 RPM with grease or oil supplied by the housing. Use when the bearing runs inside a sealed gearbox or instrument housing where the enclosure provides contamination protection.
603 ZZ bearing adds non-contact pressed steel shields (SPCC). The shield gap adds no measurable friction at this scale, retaining 59,000 RPM. Metal shields deflect coarse dust and lint. Choose ZZ for dry, clean environments: micro-motors, instrument spindles, and encoder modules.
603 2RS bearing uses nitrile rubber (NBR) contact seals. Breakaway torque is approximately 0.1 to 0.3 N-mm, limiting speed to 47,000 RPM. Choose 2RS for dental handpieces exposed to water spray, laboratory instruments in humid environments, and outdoor sensor bearings. Factory-filled with lithium grease, -40 to 120 degrees C range.
Performance
The 603 bearing is the only standard deep groove ball bearing in the 3mm-bore class. At 59,000 RPM, the 603 bearing is among the fastest in the miniature bearing range due to the small 3mm bore limiting centrifugal forces on the balls. The 5mm width is wider than the 604 bearing (4mm) despite the smaller bore, giving a larger ball complement relative to OD. Deep groove geometry provides axial capacity at roughly 25 percent of radial rating, approximately 0.037kN. GCr15 chrome steel rings and balls, stamped steel cage. Manufactured to ABEC-3 tolerance as standard.
OEM and Customization
Custom internal clearance (C2, CN, C3) available. C2 reduced clearance for dental turbines and encoder applications. At 3mm bore, CN clearance is 2 to 13 microns. Cage upgrades: PA66-GF25 polyamide for reduced rotating mass at sustained speed. 440C stainless steel for autoclave sterilization. Custom grease: low-temperature ester, PFPE for cleanroom, low-noise for audio instruments. Submit your custom bearing specification for a quote.
Applications
Micro BLDC motor shafts (ZZ)
Optical encoder modules (ZZ)
Dental handpiece turbines (2RS)
Instrument gyroscope gimbals (ZZ)
Miniature gearbox input stages (Open)
Miniature peristaltic pump rollers (2RS)
Laboratory pipetting mechanisms (2RS)
Outdoor weather sensor bearings (2RS)
FAQ
How do I choose between Open, ZZ, and 2RS for a 603 bearing? +
Choose Open for housing-lubricated assemblies reaching 59,000 RPM. Choose ZZ for dry environments with airborne dust; non-contact shields retain full speed. Choose 2RS for wet or dusty environments; rubber seals block moisture at 47,000 RPM. At 3mm bore, 2RS seal drag is 0.1 to 0.3 N-mm breakaway torque. All three share 0.23 kN load rating and ABEC-3 precision.
Why does the 603 bearing reach 59,000 RPM at such a small size? +
The high speed comes from the 3mm bore limiting centrifugal force on the balls. At approximately 6mm pitch diameter, centrifugal forces stay low even at 59,000 RPM. The stamped steel cage guides the balls effectively. For sustained operation above 47,000 RPM, use Open or ZZ since 2RS seal friction generates additional heat.
What is the difference between a 603 bearing and a 623 bearing? +
Both fit a 3mm shaft. The 603 bearing (3x9x5mm) is 5mm wide, providing better moment stiffness for cantilevered loads. The 623 bearing (3x10x4mm) is only 4mm wide with a 1mm larger OD. Choose the 603 bearing when width is available and moment stiffness matters. Choose the 623 bearing when the assembly has a strict 4mm width limit.
Can the 603 bearing be used in dental handpiece turbines? +
Yes. The 603 2RS bearing is standard for dental high-speed handpiece cartridges. The 3mm bore fits turbine shafts, 9mm OD fits cartridge housings, and 5mm width provides moment stiffness for bur loading. 2RS seals protect against water spray and debris. C2 clearance and low-noise grease are common customizations. 440C stainless steel variants are available for autoclave sterilization.
