The surface roughness of metal parts in the 3D printing industry has always been a challenge. It is dependent on many factors, but the most important factor is part geometry and orientation. The best surface characteristics are on the side that is looking up (called up-skin). The side that is looking down (down skin) typically does not have very good surface roughness. So the solution is, orienting the parts so that the amount of down skin is minimized. The surface roughness of metal AM parts can be between 2 to 15 Ra. After machining, the surface roughness is no different to a CNC machined part.