Which aspects of machining accuracy are included?

Machining accuracy refers to the degree to which the actual geometric parameters (size, shape and position) obtained after machining of a part are in accord with the ideal geometric parameters. Whether it is a part processed by the test cutting method or a batch of parts processed by the adjustment method, it may be found that some parts are different from the ideal part in some size, shape or position, and the difference between them is called the size, shape or position error, that is, the processing error. The degree of deviation between the actual geometric parameters and the ideal geometric parameters of the parts after machining is called machining error. The smaller the processing error, the higher the processing accuracy, and the larger the processing error, the lower the processing accuracy. Which aspects of machining accuracy are included?

1. Dimensional accuracy: refers to the difference between the size of the machined part and the design size. Dimensional accuracy is usually expressed by tolerance zones, such as IT01, IT0, IT1, etc., where IT represents international tolerance, the smaller the number, the higher the accuracy.

2. Shape accuracy: refers to the difference between the shape of the machined part and the design shape. The shape accuracy includes straightness, flatness, roundness, cylindricity, etc., and the error limitation of contour.

3. Position accuracy: refers to the difference between the relative position of the machined parts and the design position. Position accuracy includes coaxiality, parallelism, verticality, inclination, etc

4. Surface roughness: refers to the degree of micro-roughness of the surface of the machined parts. Surface roughness is represented by the contour arithmetic mean deviation Ra, the smaller the value, the smoother the surface.

5. Processing stability: refers to the resistance of the process system to various interference factors during processing, and the ability to maintain the stability of process parameters. Machining stability includes dimensional stability, shape stability, position stability and so on.

Machining accuracy includes dimensional accuracy, shape accuracy, position accuracy, surface roughness and machining stability. Precision machining has always been a very important link in the manufacturing industry, which directly determines the quality and reliability of products. In the processing process, the accuracy indicators should be improved as far as possible to meet the design requirements and performance.