Founded by Fred Holz during the 1870s as a small engineering shop in Cincinnati, by 1884 the forerunner of the Cincinnati Company had expanded sufficiently to have around twelve employees and become incorporated (on March 19th) as the Cincinnati Screw and Tap Co. Premises were on the third floor of a building at the southeast corner of Pearl and Plum Street and the main products, machine screws and threading taps, well established in the market place. In 1887, after a younger business acquaintance, Frederick A. Geier, had joined the company as a co-investor, a milling machine was added (designed by Holz) dedicated to shaping tap flutes. Sold into the rapidly expanding heart of the American machine-tool industry, in surrounding Ohio, the tap miller was an immediate success and quickly led to requests from other engineering concerns for the design and building of similar specialised items. In 1889 the firm was renamed, more appropriately, as the Cincinnati Milling Machine Co. , and, working from premises adjacent to Plum and Second Street, began expanded their range to include various sizes of tool and cutter grinders. In 1890 the first export order to Europe was completed, a portent of the vast expansion in sales of US machine tools to Europe was to take place over the following thirty years. In 1892 a larger plant was built on the outskirts of Ohio and then, to ensure a reliable supply of high-quality castings and other in-house needs, a new factory and foundry was established at Oakley, a suburb of Cincinnati, in 1907. Chosen because it lay alongside the Baltimore and Ohio railway, this new location gave the company access to a convenient transport system and allowed them to peruse an even more aggressive expansion program. Ranked by the number of wage earners working on machine tools (6,902) by 1942, and under the pressures of WW2, Cincinnati had become the largest in the world. By 1970, after some rationalisation, the company changed its name to Cincinnati Milacron and became heavily involved in plastic injection moulding machines. Eventually, when finally divested of the last remnants of machine-tool and grinding wheels businesses, it became Milacron Inc. - in which form it still exists today as a specialist in plastics machinery, mould technologies and industrial fluids. However, a separate branch of the company continued with machine tool building and, after various changes of ownership, today (2009) survives as Cincinnati Machine, part of the MAG Industrial Automation Systems grouping of companies.
In the decades bridging the 19th and 20th centuries technical developments in machine tools were rapid and continuous and, at the 1900 Paris World fair, Cincinnati won a gold medal for their positive, all-geared milling machine table feed-change mechanism. 1907 saw the first of the High Power machines (a branding used throughout the 20th century) - with an improved spindle drive, new feed mechanisms and logical, directional table-feed controls. This miller was also one of the first machine tools to be built using what was originally called the unit method - today called the modular approach - where, instead of machines being built individually, or in small batches, an effort was made to standardise parts across a model range of different sizes and even different types. The system also allowed machines to be built up to a particular specification, for example to have a belt, gear drive or variable-speed-drive and with tables of different sizes and travels. This proved to be a highly effective cost-saving measure and not only contributed to company profits but also attracted customers who could see the benefits of simpler maintenance and easier acquistion of spare-parts. Until the WW1 most horizontal milling machines had round overarms, a limitation that restricted their rigidity and hence metal-removal abilities. In 1917, to help overcome this limitation, Cincinnati introduced their first rectangular overarm models, the No. 4 and No. 5 High Power machines; these also incorporated several other useful aids to faster production and operator ease including knee ways of the square gibbed type, rapid power traverses and changes of table feed-rate obtainable conveniently from the front. In the years that followed anti-friction (taper-roller) bearings were introduced and, in 1927, the Hydromatic, the first milling machine to enjoy the benefits of a smooth-running and very powerful hydraulic table drive. In 1922 a buy-out of the Cincinnati Grinders Company gave access to centerless grinding-machine technology and by 1926 a separate organisation, Cincinnati Grinders Incorporated was been formed with initial efforts aimed at improvements to the existing designs and development of new centre grinders. By now, such was the demand that machines were not only being built in America but also, to meet European requirements, at a large factory at Tyburn, in Birmingham, England. In later years other European branches were opened including Cincinnati-Chomienne S.A., based in Ville-franch-sur-Saone (where a new factory was constructed in 1967) and, during the 1950s, Cincinnati-Nederland N.V. in Vlaardingen, Holland.
In 1929 a milestone was reached, the introduction of the first Dial Type miller. This famous model, which continued in various forms until the 1980s, was to become (with the smaller 2M1, 2ML and later versions) the mainstay of the factory's general-purpose line. From the start, the machine was fitted with two important features: dual front and rear controls and power selection of feeds and speeds.
Following the end of WW2, in 1945, the company line expanded to include machines for broaching, die sinking, the projection profile grinding of tiny parts, automatic three-dimensional milling, hardening and metal forming, etc. By the end of the 1940s the company had established separate divisions to handle (amongst other things) special work involving the manufacture of one-off commissions, very large machine tools, modifications and adaptations to the regular range and complete transfer machines with multi-station machining capacity for handling components through sequential stages of manufacture without human intervention. The company even made its own range of cutting fluids and grinding wheels.
In post war years two ram-head milling of interest to the both general and specialist workshops were offered: the versatile Toolmaster (a Bridgeport competiror) and the Contourmaster, a machine intended for die sinking and reproduction work but also useable for lighter, general purpose duties.
Cincinnati machine tools were always regarded as a safe buy and the company were able to offer not only machines attuned to local needs but also a proper spares and service organisation to back them up. In the writer's collection is correspondence between Cincinnati in Birmingham, England, and various local engineering firms. In this the most mundane of enquires is given the closest attention and technical enquires answered in detail, with useful references to how other firms had solved similar problems.
During most decades of the 20th century we find a range of Cincinnati milling machines built in three general classifications: die sinking and profiling, general purpose and production. Many models became well established and were developed steadily though three or more generations to become well-proven, reliable units available in sizes and sub-types to cover virtually every need of the production, repair or maintenance shop.
One of many interesting developments from the UK branch during the 1970s was the introduction (in 1971) of the 2MK, a machine designed from the outset to be manufactured using NC machine tools. This type widely exported, with Cincinnati agreeing a contract with Iran for 180 complete examples to be delivered to Machine Sazi Tabriz, a Government plant some 320 miles north-east of Tehran. Following this further batches were to be shipped as sub assemblies and individual parts for assembly at Sazi Tabriz until finally, after some 6 years and with help from the Birmingham factory, it was envisaged that the Iranians would be able to manufacture the machine themselves.
Cincinnati Dial Type Millers
Early Cincinnati Dial Type Millers
Late Cincinnati Dial Types
Operating the Cincinnati Dial Type
Cincinnati Cinedo Miller
Millers 2MI, 2ML 203, 205, 307 & 410
8" x 18" Tool & Die Miller
Cincinnati Serial Numbers
Cincinnati Tool & Cutter Grinder No. 2
Operation, Maintenance and Parts Manuals
are available for most Cincinnati Millers
Cincinnati Milling Machines
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