Because the plating layer has a certain thickness, after the surface treatment of the part, the size of the part will inevitably be changed. Generally, the dimensions and tolerances of the parts specified on the design drawings refer to the final dimensions and tolerances of the parts. If the parts do not have the requirements of coordination, it is still feasible to perform electroplating or electroless plating on the final dimensions of the parts.
If the accuracy of the part is high and the mating gap after assembly cannot adequately accommodate the thickness of the plating layer and its deviation, then plating on the final size of the part is detrimental to the assembly and workability of the product. In order to solve the problem of dimensional fit after plating of parts with matching requirements, the pre-plating process size of the part must be determined through consultation with the part design and process department, and the thickness of the plating layer and the dimensional deviation of the plating must be reserved in advance. It must be noted that it is not feasible to reserve only the thickness of the plating layer and not the thickness deviation that may occur during plating.