In the actual production of guide sleeve die forgings, due to the influence of various process factors, the actual size of the guide sleeve die forgings cannot be equal to the nominal size, and there will be deviations in both the height direction and the horizontal direction. Therefore, a limited deviation range is allowed for the guide sleeve die forgings. The part where the largest dimension of the guide sleeve die forging is larger than the nominal dimension of the guide sleeve die forging is a positive tolerance, and the part where the minimum dimension of the guide sleeve die forging is smaller than the nominal dimension of the guide sleeve die forging is a negative tolerance, as shown in the figure "Various Dimensions and Tolerance Allowances of Guide Sleeve Die Forgings".