I'm not quite sure how to do the brushed metal look. Using shaders from
http://www.poliigon.com works really well most of the time (even though they're designed for Blender/Cycles) but I haven't figured out how to incorporate such a map like the one attached. It's called a direction map. It doesn't work when applied as a normal map, but kinda does when I decrease the "power" a lot. I'm currently using a B&W version as a roughness map but that's not exactly the effect I'm going for either.