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 CHAPTER VII GENERAL MACHINE SHOP Machinery and Methods—General. To describe the many processes which various parts of the engine undergo in the general machine shop would be a task far beyond the possibilities of this book. This shop is provided with the lathes, planing, shaping, and slotting machines such as are to be found in all large engineering shops, and in addition there are many special modern tools, such as automatic lathes for making stays, pins, studs, etc., grinding machinery, and above all, milling machines. Formerly the machining was performed on the first mentioned machine tools of standard pattern, and then passed on to the fitters to be finished by filing, scraping and the other well known fitters’ methods. Nowadays the work is done and completed as far as possible on milling and grinding machines, so that as little fitting as possible is required, many of the parts going direct from the machines to the erecting shop to be put together on the engine. The former processes of planing, shaping and slotting are now very largely replaced by milling. In milling machines the work is machined by revolving vertical or horizontal serrated cutters, which produce a fine finished smooth surface. These cutters can be shaped, or two or three of