In the manufacturing of rolling bearings, superfinishing serves as the final critical step in ring processing—directly influencing the bearing’s vibration noise, fatigue life, and assembly quality. As an advanced grinding tool, Cubic Boron Nitride (CBN) superfinishing oilstones stand out for their unique advantages in bearing raceway processing and are increasingly widely adopted by manufacturers worldwide. Below is a detailed breakdown of their core features, applicable materials, working principles, and processing workflows to support optimized bearing production.
1. Core Product Features
CBN superfinishing oilstones are engineered specifically for bearing raceway precision, with two standout performance traits:
Tailored for Dual-Stage Superfinishing: Designed exclusively for the superfinishing of bearing inner and outer raceways, they excel in both primary superfinishing (rough grinding) and secondary superfinishing (mirror polishing). This dual capability significantly boosts raceway surface finish and roundness accuracy—for example, after processing, raceway surfaces become far smoother, and roundness errors are tightly controlled within minimal ranges, a key factor in ensuring stable long-term bearing operation.
Superior Mechanical Properties: They boast excellent elasticity, strong cutting force, and high wear resistance. The good elasticity allows the oilstone to better conform to the raceway’s contour during grinding, ensuring uniform material removal across the entire surface. The robust cutting force enables efficient material reduction, while high wear resistance extends the oilstone’s service life—reducing tool replacement frequency and lifting overall production efficiency.
2. Applicable Materials & Industries
Versatility is another strength of CBN superfinishing oilstones, making them suitable for honing a range of components and materials:
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Target Components: Cylinder liners, cylinder liner seats, and connecting rods.
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Compatible Materials: Various cast irons, ceramics, aluminum alloys, and chrome-plated materials—covering the most common substrates in precision machining.
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Key Application Industries: They are widely used in automotive, motorcycle, refrigeration, bearing manufacturing, shipbuilding, and aviation sectors. In the automotive industry, for instance, they are applied to hone engine cylinder liners, directly enhancing the engine’s performance and long-term durability.
3. Working Principle
The precision of CBN superfinishing oilstones stems from a well-defined operational mechanism:
Under low-pressure, elastic conditions, the oilstone (embedded with fine-grained abrasives) is pressed against the workpiece surface. As the workpiece rotates, the oilstone performs rapid reciprocating oscillations in a controlled pattern perpendicular to the workpiece’s rotation direction. Throughout the process, optimal lubrication and cooling are maintained to reduce surface roughness and improve geometric accuracy.
In terms of achievable precision: When paired with domestic superfinishing equipment, the processed surface can reach a roughness (Ra) of approximately 0.1μm; with imported equipment, Ra can be reduced to 0.04μm or lower—meeting the strict precision requirements of high-performance bearings.
4. Bearing Raceway Processing Technology
Bearing raceway manufacturing follows a sequential, precision-focused workflow, with superfinishing as the final quality-determining step:
The standard process route is turning → heat treatment → grinding → superfinishing:
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Turning: Shapes the raceway into its basic form, laying the foundation for subsequent precision steps.
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Heat treatment: Enhances the material’s hardness and mechanical strength, ensuring the raceway can withstand operational stress.
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Grinding: Refines the raceway’s shape and dimensional accuracy, narrowing down deviations before the final finish.
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Superfinishing: The critical last step—using CBN superfinishing oilstones to achieve the ultra-smooth surface and tight geometric tolerance required for reliable bearing performance.
For manufacturers aiming to elevate bearing quality, reduce production costs, and enhance efficiency, CBN superfinishing oilstones provide a proven solution for raceway processing.
To learn more about how these tools can be tailored to your specific material or production needs, reach out to our technical team for personalized guidance.
