*Internationally Accepted Grades (ISO Standard)

From Lowest Precision to Highest Precision: P0 (Standard Grade) < P6 < P5 < P4 < P2

*Applicable Scenarios for Each Grade

1. P0 Grade (Standard Grade, Most Commonly Used): The default standard for the vast majority of automotive wheel hub bearings, truck tapered roller bearings, general motor bearings, and construction machinery bearings. Allows for relatively large dimensional tolerances and rotational errors; meets general transmission and vehicle operating conditions.

90% of commercial vehicle and passenger car DAC wheel hub bearings and Class 3 tapered roller bearings on the market are P0.

2. P6 Grade (Higher Than Standard Grade): Between P0 and P5; used for equipment requiring smooth operation and slightly lower vibration. P6 can be selected for some bus wheel hubs, small and medium-sized speed reducers, and conveying equipment.

3. P5 Grade (Precision grade): Used in general machine tool spindles, pumps, precision reducers, and small to medium-sized high-speed equipment. P5 is rarely used in automotive bearings due to significant cost increases.

4. P4 Grade (Ultra-precision): Used in high-precision machine tool spindles, high-speed grinding machines, and precision robot bearings; prices have increased dramatically.

5. P2 Grade (Highest Precision): Used in ultra-high precision laboratory instruments and coordinate measuring machines; almost never used in mass-produced industrial applications.

Important Note: Precision grade ≠ maximum speed limit. Precision controls dimensional consistency and rotational runout; speed is also affected by clearance, lubrication, and structure.