Bearing Accuracy Level

 

The ISO standard defines bearings with different accuracy grades, including P0, P6, P5, P4 and P2 grades. These grades reflect the machining accuracy and performance of the bearings. The following is a detailed introduction to each grade and its main application scenarios:

 

ISO P0 Level

• Machining accuracy: The ISO P0 grade is the most common standard accuracy grade, also known as the general accuracy grade. It indicates that the tolerance of the bearing is within the normal range and meets the requirements of most general applications.
• Radial deviation (μm): In a bearing with a diameter of 25mm, the radial deviation is usually 0~7μm.
• Axial deviation (μm): In a bearing with a diameter of 25mm, the axial deviation is usually 0~10μm
• Main application scenarios: ISO P0 grade bearings are generally used in general industrial applications, such as motors, transmissions, agricultural machinery, etc. These applications have general requirements for bearing accuracy, but have requirements for performance and reliability.

 

ISO P6 Level

• Machining accuracy: The ISO P6 grade is higher than P0, indicating that the bearing has a smaller tolerance and higher machining accuracy.
• Radial deviation (μm): In a bearing with a diameter of 25mm, the radial deviation is usually 0~5μm.
• Axial deviation (μm): In a bearing with a diameter of 25mm, the axial deviation is usually 0~8μm.
• Main application scenarios: ISO P6 grade bearings are usually used in applications with high precision requirements, such as high-speed rotating machinery, precision instruments and tools, etc.

 

ISO P5 Level

• Processing accuracy: ISO P5 grade is a high-precision grade, indicating that the tolerance of the bearing is very small and the processing accuracy is very high.
• Radial deviation (μm): In a bearing with a diameter of 25mm, the radial deviation is usually 0~3μm.
• Axial deviation (μm): In a bearing with a diameter of 25mm, the axial deviation is usually 0~6μm.
• Main application scenarios: ISO P5 grade bearings are usually used in high-precision machine tools, precision processing equipment, high-speed fans and power tools, etc., which require extremely high operating accuracy and stability of the bearings.

 

ISO P4 Level

• Processing accuracy: ISO P4 grade is an extremely high-precision grade, the tolerance of the bearing is very small, the processing accuracy is very high, and it is usually used in applications with extremely high requirements for bearing performance.
• Radial deviation (μm): In a bearing with a diameter of 25mm, the radial deviation is usually 0~2μm.
• Axial deviation (μm): In a bearing with a diameter of 25mm, the axial deviation is usually 0~4μm.
• Main application scenarios: ISO P4 grade bearings are mainly used in precision machining, optical equipment, high-speed motors and precision measyring equipment, and have extremely high requirements for bearing stability, accuracy and life.

 

ISO P2 Level

• Processing accuracy: ISO P2 grade is the highest accuracy grade, indicating that the tolerance of the bearing is extremely small and the processing accuracy is extremely high. It is usually used for extremely precise applications.
• Radial deviation (μm): In a bearing with a diameter of 25mm, the radial deviation is usually 0~1μm.
• Axial deviation (μm): In a bearing with a diameter of 25mm, the axial deviation is usually 0~2μm.
• Main application scenarios: ISO P2 grade bearings are usually used in fields with extremely high precision requirements such as ultra-precision machine tools, optical precision instruments, aerospace devices, etc., and have very strict requirements for the running accuracy, stability and life of the bearings. 

 

Choosing the appropriate accuracy grade depends on the requirements of the specific application, and factors such as load, speed, vibration, etc. that the bearing is subjected to during operation need to be taken into account to ensure the performance and reliability of the bearing.

 

Bearing accuracy level comparison table

Standards		Accuracy level
ISO	ISO492	P0	P6	P5	P4	P2
China	GB307	P0(G)	P6(E)	P5(D)	P4(C)	P2(B)
Germany	DIN	P0	P6	P5	P4	P2
Japan	JIS	0	6	5	4	2
American	ANSI	ABEC1	ABEC3	ABEC5	ABEC7	ABEC9