Zamak, or more specifically Zamak V or 5, is an excellent die casting material except fir the Zinc Pest problem, which is caused, as Craig indicated, by contaminated feed stock. So only a relatively small percentage of total production would be affected. And basically, if the parts haven't already crumbled, they aren't going to. I will also remind all that were it not for the availability of Zamak or something similar, there would be no relatively plentiful supply of Atlas machines around because they would not have been sold in anything like the quantities that they were. Had Atlas Press attempted to get into the machine tool business competing with South Bend and Clausing without the advantage of all of the cheap to produce die-case parts, they would most likely have been out of business before the beginning of WW-II. And this Forum wouldn't exist. As it was, Atlas tried to make a few things out of Zamak that they shouldn't have. The first group they corrected fairly soon. About 43 years later, those people were probably all dead and the second mistake appears to have been the main reason for shutting down production of the 6" Atlas.