Comparison of dimensional tolerance grades for metal AM processes

Each manufacturing process produces geometric features with some dimensional errors from the ideal nominal geometry. The knowledge of the dimensional tolerances associated with the specific fabrication process is fundamental for choosing the proper sequence of finishing operations to meet the design requirements. While the ranges of dimensional tolerances for traditional manufacturing processes are well mapped in the literature, a little information is available for additive manufacturing (AM) techniques. In this paper, a benchmarking analysis is carried out between two different AM processes for metals and the dimensional accuracy of each AM machine is defined using the ISO IT grades of a reference artifact.