Some stocks in this space are Southern Copper (PCU) and Allegheny Technologies (ATI). At this point, returns look great looking back at the trailing cycle, but looking forward we could be going downhill as the cycle bottoms. Also, copper and steel is copper and steel regardless of who supplies it. Buyers can often get these materials from a variety of providers, so there is no intrinsic moat qualities to these businesses.
The one exception would be those firms that own a very unique property or have the market for a particular commodity cornered (no other competitor can get access to it). However, these situations are rare.