Seventeen millimeters is the shaft diameter at which small electric motors begin to produce useful torque. The 6903 bearing matches this bore with a 30mm outside diameter and 7mm width, delivering 4.60 kN of dynamic load capacity in the most compact envelope in the 6900 series above 15mm bore. Three sealing configurations (Open, ZZ, and 2RS) let you trade speed for contamination protection without changing the bearing envelope.
For any inquiries, please contact with our Supporting Team at sales@yuanhecd.com.
Deep groove ball bearing 6903 with 17mm bore, 30mm OD, and 7mm width. Three sealing configurations (Open, ZZ, 2RS) from the same GCr15 ring-and-ball set. ABEC-3 precision, 4.60 kN dynamic load, 2.55 kN static load, up to 22,000 RPM.
Bore x OD x Width
17x30x7 mm
Dynamic Load (Cr)
4.60 kN
Static Load (Cor)
2.55 kN
Max Speed
22,000 RPM
Sealing
Open / ZZ / 2RS
Precision
ABEC-3
| Model | 6903 |
| Type | Open / Shielded / Sealed |
| Bore Dia. | 17 mm |
| Outside Dia. | 30 mm |
| Width | 7 mm |
| ABEC Tolerance | ABEC-3 |
| Dynamic Load Capacity | 4.60 kN |
| Static Load Capacity | 2.55 kN |
| Max. RPM | 22,000 RPM |
| Temp. Range | -40~120°C |
| Material | GCr15 Chrome Steel |
| Seal / Shield Material | NBR rubber (2RS) / SPCC steel (ZZ) |
| Lubrication | Polyurea grease (standard) |
The 6903 bearing ships in three seal variants from the same GCr15 ring-and-ball set. The choice is about which operating condition the bearing faces, not about bearing quality or load rating. All three configurations share 4.60 kN dynamic and 2.55 kN static.
6903 Open bearing carries no seals and reaches 22,000 RPM. The exposed ball path accepts re-greasing and oil-mist lubrication, making it the right choice inside gearboxes, oil-bath pump housings, and motor end bells where the enclosure already blocks contaminants. Open bearings are also the lightest configuration; every gram matters in hand-held power tools and drone propulsion systems.
6903 ZZ bearing uses two pressed SPCC steel shields locked into outer-ring grooves. The shields do not contact the inner ring, so there is no friction penalty. The bearing retains 22,000 RPM and arrives factory-filled with polyurea grease rated for the full temperature range. The labyrinth gap blocks splashes and coarse particles. Choose ZZ for belt-driven machinery, fan motors, and enclosed power tools where occasional oil mist or coolant splash reaches the bearing.
6903 2RS bearing uses nitrile rubber (NBR) contact seals bonded to steel inserts. The seal lip rides in a groove on the inner ring, forming a positive barrier against fine dust, moisture, and direct spray. This protection comes with a speed penalty: contact friction limits the 2RS variant to approximately 17,000 RPM. Choose 2RS for agricultural sprayers, outdoor conveyor rollers, food-processing equipment exposed to washdown, and any application where the bearing sees direct water or abrasive grit.
At 4.60 kN dynamic and 2.55 kN static, the 6903 bearing carries 35% more load than the 6902 bearing (15mm bore, roughly 3.4 kN dynamic). It delivers that gain while adding only 2mm to both bore and OD. For engineers moving up from a 15mm shaft design, the 6903 bearing often fits the same housing envelope with a simple rebore, eliminating the need to redesign surrounding components.
Within the 6900 thin-section series, the 6903 bearing holds a balanced position. The 6902 bearing works with a 15mm shaft at lower load. The 6904 bearing jumps to a 20mm shaft and 6.38 kN dynamic, but its 37mm OD demands 7mm more radial space. If the housing bore is fixed at 30mm and the shaft is 17mm, the 6903 bearing is the highest-capacity option available in that form factor.
ABEC-3 tolerance holds radial runout within 0.010mm. For motor and pump applications, this is sufficient. The 7mm width keeps the bearing narrow enough for stacked pairs in gearboxes and compact enough for hand-held power tools where every millimeter of tool grip diameter counts.
Yuanhe supplies the 6903 bearing with C3 radial clearance and polyurea grease as standard. For OEM orders, the following are available:
Submit your bearing drawing or part number for a custom quote. MOQ for modified clearance or grease specifications starts at 500 pcs.
English
French
German
