thanks man, thats some intetesting info I'll havta look into a bit more. In my hopes and dreams I would have a place for my own little foundry eventually...but one thing at a time obviously...I'm no expert but AIUI if cast iron is cooled very quickly, it becomes VERY hard. If it is intended to be machined, it should be cooled quite gradually. When casting weight plates, I doubt they would go to the extra bother of cooling slowly. I believe you can anneal the metal by heating and then slowly cooling. I think I've read that tossing the pieces into a bonfire will get them hot enough and the ashes will cool slow enough. Never tried it.