The accuracy grade of ball screw is an important indicator to measure its transmission accuracy. It is mainly divided into two systems: domestic standard (P grade) and JIS standard (C grade). The following is a detailed classification of the two standards and their characteristics:
1. Domestic standard (P grade)
The domestic standard divides the accuracy of ball screw into 7 grades, from high to low, namely P1, P2, P3, P4, P5, P7, and P10. Among them, P1 grade has the highest accuracy and P10 grade has the lowest accuracy.
P1 grade: The motion accuracy is within 0.012mm, suitable for high-precision mechanical equipment, such as the feed system of precision machine tools.
P2 grade: The motion accuracy is within 0.007mm, used for high-precision equipment, such as precision grinders and CNC lathes.
P3 grade: The motion accuracy is within 0.005mm, suitable for ultra-precision equipment, such as high-end instruments in the aerospace field.
P5 level: The travel variation within any 300mm travel is 0.023mm, which is widely used in CNC machine tools and their transformation.
P7 level: The accuracy is relatively low, suitable for occasions where the accuracy requirements are not stringent, such as the joints of industrial robots.
P10 level: The lowest accuracy, generally used for simple material conveying equipment, etc.
2. JIS standard (C level)
The JIS standard divides the accuracy of ball screws into 6 levels, from high to low, namely C0, C1, C3, C5, C7, and C10. Among them, C0 has the lowest accuracy and C5 has the highest accuracy.
C0 level: Basic accuracy level, suitable for occasions with low speed or low load requirements, such as small automation equipment.
C1 level: The accuracy is higher than C0 level, suitable for industrial automation fields such as machine tools and CNC equipment.
C3 level: High accuracy level, suitable for precision processing machinery and semiconductor equipment.
C5: Ultra-precision grade, suitable for occasions requiring high accuracy such as optical equipment and satellite navigation.
C7: The stroke variation within any 300mm stroke is 0.050mm, suitable for mid-to-high-end automated production lines and printing equipment.
C10: Lower accuracy, suitable for occasions with low precision requirements.
3. Comparison of the two standards
The accuracy of P5 is between C5 and C7, which is basically equivalent to C6 (0.025mm).
The accuracy of C7 is lower than that of P5, but higher than that of P7.
4. Application scenarios
Ball screws of different accuracy levels are suitable for different application scenarios. For example, high-precision grades (such as P1, C5) are suitable for precision machine tools and high-end instruments, while low-precision grades (such as P10, C10) are suitable for simple material conveying equipment.
By understanding these accuracy grades, users can choose suitable ball screw products according to specific needs to achieve the best transmission effect.
