During the last decade, this metal MEX process has attracted more attention due to the due to the as-mentioned advantages and the familiarities with conventional polymer 3D printing, which is the metal-fused filament fabrication process (FFF), usually called fused deposition modelling (FDM). Figure 1 shows the number of publications relating to metal MEX per year and the cumulative number. From 1996 to 2015, there are very few publications per year. However, the number has significantly increased since 2015. It is noted that publications were searched mainly from several databases, e.g., Web of Science, Scopus and Google Scholar, using several searching keywords, e.g., “metal material extrusion”, “metal fused deposition modelling”, “metal fused filament fabrication” and “Ultrafuse 316L”, including the references of related articles. The three prior review articles focusing on metal MEX [4,5,30] provide a good overall review of the subject but do not address the achievable mechanical properties in detail.