Tutorial - PBR and Metals Technics

I see a lot of people with some problems when creating metals. Metals are very tricky some times, but when you get it it becomes one of the coolest stuffs to create. With PBR shaders on the market we can get some really cool good looking metals around there, and here I am giving some tips, inside you can double click on the numbers and see some infos. Metals: Pure metals has no diffuse on it, all it colors comes from the reflection, this is how our physical world works, and it is going to be exactly how you can give a cool look on a PBR shader. Each render or engine may work a little different on the sliders, but the results are always be the same. I add all the information on the forum at artworks. Link: http://forum.sketchfab.com/t/pbr-and-metals-technics/2070