Aerospace is one of the most important application fields of metal 3D printers. By SLM technology, various kinds of metal alloys such as Ni based super alloys, stainless steels, Aluminum and Titanium alloys, along with very complex and elegant shapes can be produced conveniently. In the other hand, in aerospace we need to reduce weight and eliminate part assembly by integrated manufacturing, which is one of the main characteristics of SLM technology. So, SLM seems to be a perfect alternative for traditional manufacturing methods in this industry.