What Are Silicon Nitride Bearing Rollers?
Silicon nitride bearing rollers are cylindrical ceramic rolling elements used inside bearings to transfer load while reducing friction between rotating components. They are commonly used with steel raceways in hybrid bearings or with ceramic raceways in full-ceramic bearing assemblies.
Because Si₃N₄ ceramic has low density, high hardness, good wear resistance and electrical insulation, these rollers are suitable for high-speed spindle bearings, electric motor bearings, process pump bearings and rotating equipment exposed to moisture, mild chemicals or current leakage.
Why Choose Si₃N₄ Rollers Instead of Steel Rollers?
- Low Mass for High Speed
Silicon nitride rollers have much lower density than steel, helping reduce centrifugal load and dynamic stress in high-speed bearing assemblies. This is useful for machine tool spindles, precision motors and rotating systems where vibration control is important. - Electrical Insulation
Si₃N₄ ceramic is electrically insulating, so it helps reduce the risk of current passing through the rolling contact zone. This makes it valuable for inverter-driven motors, generators and VFD systems when used together with proper grounding design. - Wear and Surface Stability
Polished silicon nitride rollers can provide stable surface contact and reduced friction variation under suitable lubrication. Surface finish can be specified according to the bearing speed, preload and noise requirements. - Corrosion Resistance
Silicon nitride has better resistance to moisture and many mild chemical environments than bearing steel. It is suitable for process pumps, blowers and humid industrial environments where steel rollers may corrode or pit. - Custom Geometry
Roller diameter, length, chamfer, roundness, cylindricity and surface finish can be customized to match raceway geometry, preload requirements and assembly clearance.
Silicon Nitride Bearing Rollers Properties
1. Silicon Nitride Bearing Rollers Technical Data and Grade Options
| Si3N4 Type | Gas pressure sintering Si3N4 | Hot pressing sintering Si3N4 | High thermal conductivity Si3N4 |
| Density (g/cm3) | 3.2 | 3.3 | 3.25 |
| Flexural Strength (MPa) | 700 | 900 | 600~800 |
| Young Modulus (GPa) | 300 | 300 | 300~320 |
| Poisson's ratio | 0.25 | 0.28 | 0.25 |
| Compressive strength (MPa) | 2500 | 3000 | 2500 |
| Hardness (GPa) | 15 | 16 | 15 |
| Fracture toughness (MPa*m1/2) | 5~7 | 6~8 | 6~7 |
| Maximum working temperature (℃) | 1100 | 1300 | 1100 |
| Thermal conductivity (W/m*K) | 20 | 25 | 80~100 |
| Thermal expansion coefficient (/℃) | 3*10-6 | 3.1*10-6 | 3*10-6 |
| Thermal shock resistance (ΔT ℃) | 550 | 800 | / |
2. Roller Grade Specifications (Unit: μm)
| Tolerance Grade | Ra | ||
|---|---|---|---|
| Rolling Surface (max) | End Face (max) | Chamfer (max) | |
| 0 | 0.1 | 0.125 | 1.25 |
| I | 0.125 | 1.16 | 1.25 |
| II | 0.16 | 0.25 | 2.5 |
| III | 0.25 | 0.32 | 2.5 |
Si3N4 Bearing Roller Specifications
| Silicon Nitride Bearing Rollers | ||
| Item No. | Diameter（mm) | Height（mm) |
| AT-SIN-GZ001 | 3 | 4 |
| AT-SIN-GZ002 | 3 | 5 |
| AT-SIN-GZ003 | 3 | 5.5 |
| AT-SIN-GZ004 | 5 | 6.5 |
| AT-SIN-GZ005 | 5 | 8 |
| AT-SIN-GZ006 | 10 | 10 |
Si₃N₄ Bearing Ceramic Rollers Packaging
- Each roller is individually packed in anti-static foam trays.
- Sealed and moisture-proof packaging is available for export.
