11-June-2012 While Bill works on the replacement screw in the big lathe, I begin hogging the bar of cast iron down to size to make replacement nuts. The first nuts were steel, which is the same material as the screws and we believe contributed to the sieze condition. Aparently I did not use the feed and speed calculator correctly for my shell mill. I tore one of the cemeted carbide inserts out of the holder, shutting me down until I can get a replacement. maybe the pretty golden chip sparks or the pile of blue cast iron chips should have tipped me off that something was wrong before I broke the tooth.