The surface roughness of machine tools will affect the actual fitting properties and fitting accuracy of parts.
If the fitting surface of machine tool parts is rough, a large shear pressure will be generated at the top of the machine tool surface during clearance fitting, which is easy to be cut off during relative movement, so that the actual fitting clearance will be increased, thus reducing the fitting accuracy; In the interference fit, the bumps on the surface are sheared and flattened during assembly, which reduces the actual interference, reduces the strength of the interference fit, and affects the service life of machine tool parts. Therefore, in order to improve the reliability and stability of fitting, the machine tool must specify a smaller roughness value for the surface with fitting requirements. Surface residual stress will cause deformation or cracks of parts, cause changes in the shape or size of machine tool parts, and also have a certain impact on the fitting accuracy.
