What are these Hastings rings made of??

Does anyone know what these Hastings rings are made of?? The Hastings numbers are 7029. I bought them from MAP in Florida. Their stock number is R26730/H. I could not get a reply from Hastings. How long does it take for these rings to break in if done properly??? Thanks again!!

I didn't go to the website & research you particular part number, but the Hastings rings I put in my 750 were simple cast iron. They broke in almost immediately.

Dollars to a donut, that's what you have too.

Thanks to all that helped with tech information 850 Commando

The 850 commando runs like a bat out of hell and I want ot thank all of you who helped me with technical information. Geeze Louise I wish we all had this kind of internet help when I was in High school in 1971. You guys make it mistake proof when it comes to restoring an old classic bike. I am on the road riding this warm weekend we are having down here in Texas. After the Nascar race I intend to get her out for a full wekend of break in time!! Again Thank You guys /////are the best --Mark Cigainero In Fort Worth Texas-----