I am having trouble finding tier 4 materials (DURASTEEL) and I have no clue where to find it or how to make it. Apparently it is craftable but how exactly? Thank You! Ok, whoops just found out you need a 'Titanium bar' and a 'Silver bar' at a industrial furnace to make it. I have an industrial furnace but still can't find the craft option. Do you need to unlock the recipe, and if so how? Thank You!