We ship to some various mills but it took us a long time to get the needed volume. For Al wheels, we do about a trailer a week. For rotors, we also do about a trailer (semi: 40,000 pounds) a week. Any less than that and they typically do not want to bother. The general rule of thumb is the larger the loads you get on a consistent basis, the higher up the processing path you can go. You might be better off talking to your scrap yard etc about giving you a higher price for the larger quantity. Most will do that.