History Text d 1810s-1830s

Milling machines evolved from the practice of rotary filing—that is, running a circular cutter with file-like teeth in the headstock of a lathe. Both rotary filing and later true milling were developed in order to reduce the time and effort spent on hand-filing. The full, true story of the milling machine's development will probably never be known, because much of the early development took place in individual shops where generally no one was taking down records for posterity. However, the broad outlines are known. Rotary filing long predated milling. A rotary file by Jacques de Vaucanson, circa 1760, is well known. It is clear that milling machines as a distinct class of machine tool (separate from lathes running rotary files) first appeared between 1814 and 1818. Joseph W. Roe, a respected founding father of machine tool historians, credited Eli Whitney with producing the first true milling machine. However, subsequent scholars, including Robert S. Woodbury and others, suggest that just as much credit belongs to various other inventors, including Robert Johnson, Simeon North, Captain John H. Hall, and Thomas Blanchard. (Several of the men mentioned above are sometimes described on the internet as "the inventor of the first milling machine" or "the inventor of interchangeable parts". Such claims are oversimplified, as these technologies evolved over time among many people.) The two federal armories of the U.S. (Springfield and Harpers Ferry) and the various private armories that shared turnover of skilled workmen with them were the centers of earliest development of true milling machines (as distinct from lathe headstocks tooled up for rotary filing).

James Nasmyth built a milling machine very advanced for its time between 1829 and 1831. It was tooled to mill the six sides of a hex nut that was mounted in a six-way indexing fixture.

A milling machine built and used in the shop of Gay & Silver (aka Gay, Silver,, & Co) in the 1830s was influential because it employed a better method of vertical positioning than earlier machines. For example, Whitney's machine (the one that Roe considered the very first) and others did not make provision for vertical travel of the knee. Evidently the workflow assumption behind this was that the machine would be set up with shims, vise, etc. for a certain part design and successive parts would not require vertical adjustment (or at most would need only shimming). This indicates that the earliest way of thinking about milling machines was as production machines, not toolroom machines.

Text e. 1840s-1860

Some of the key men in milling machine development during this era included Frederick W. Howe, Francis A. Pratt, Elisha K. Root, and others. (These same men during the same era were also busy developing the state of the art in turret lathes. Howe's experience at Gay & Silver in the 1840s acquainted him with early versions of both machine tools. His machine tool designs were later built at Robbins & Lawrence, the Providence Tool Company, and Brown & Sharpe.) The most successful milling machine design to emerge during this era was the Lincoln miller, which rather than being a specific make and model of machine tool is truly a family of related tools built by various companies over several decades. It took its name from the first company to put one on the market, George S. Lincoln & Company.

During this era there was a continued blind spot in milling machine design, as various designers failed to develop a truly simple and effective means of providing slide travel in all three of the archetypal milling axes (X, Y, and Z—or as they were known in the past, longitudinal, traverse, and vertical). Vertical positioning ideas were either absent or underdeveloped.