Difference between Cast Iron and Heavy Iron

[TheeFirewoodGuy]

I bought a commercial lathe yesterday. One piece alone weighs nearly a ton. It came with many different pieces. All of it is iron, but some pieces of the same size are much heavier than others. Any easy way of telling the difference between regular cast iron and heavy iron, other than by weight?
My yard is paying $260 for steel, $280 for iron, and I think $310 for heavy, so this knowledge would be pretty 'valuable'.

[RustyDollars]

My yard told me that if you can break it then it's cast. If it dents or bends then it is steel.

[TheeFirewoodGuy]

Yeah, steel is pretty easy to differentiate from iron. I've never really accumulated much iron in the past, so I never bothered sorting the different types of iron. One day, I was looking at the price list, and noticed that they were paying $280 for iron, and $350 for hubs and rotors! Then I noticed they were also paying more for heavy iron than for cast iron. Yesterday I ended up buying a couple loads of iron, so I am even more concerned about maximizing profit now. I've never learned the difference between heavy and cast iron, so I'm just trying to see what info I can find.

[KzScrapper]

Cast is grainier or has more texture and I look for the seam where the molds came together, whereas iron that has been forged or rolled is smoother.

[taterjuice]

A cast cam shaft will bust in half if you throw it on the ground. Engine blocks, brake drums and rotors all cast iron. Along with seems, you can almost always find a casting number if it's cast iron. My yards always pays more for cast than prepared. Not all yard do tho.

[Bear]

I don't recall enough to give any extended lectures on the subject, but carbon content is one of the main differences in irons and steels, along with different impurities, alloys, and heat treatments

what's known as "heavy", and "ductile", might be the same

[TheeFirewoodGuy]

Ah, cool. I have enough iron that I was attempting to sort it. Now that you mention that, I remember the 'heavy' being smoother. And it would be logical for cast to have a seem... It is casted. I also noticed that a strong magnet is tougher to pull off of heavy iron, and is easier to pull off of cast iron. Due to the weight difference between cast and heavy pieces of similar size, and the difference in magnetic attraction, I have come to the assumption that cast iron is an alloy. Thanks for pointing out those differences, Kz.