I'm sure that I'm starting to become afmiliar to you folks by now, so I'll spare you the context. I'm starting to suspect the old shower drain below my concrete basement pad is cast iron instead of lead (it seems too hard for lead). Does anyone know of a sure fire way of identifying which material it is?

Is there any rust on the drain flange, lead won't rust but does turn a dull grayish color. Scratch it with a pocket knife, if its lead it will cut and expose a very shiny silver color.

Cast iron's hard and brittle while lead's soft and pliable. Like Bob sez, "scrape it with a knife." Good luck, Tom