Brown & Sharpe screw machines had been a cornerstone of American manufacturing for many decades, known to be the best productivity solution for many turned bar products. The Brown & Sharpes were built as single spindle automatics, designed to use form tools and special cams.
Today, some of these older machines have been retrofitted with CNC Milling servo motors to aid flexibility and eliminate the need for making a special set of cams to optimize a process. Retrofitted and cam operated machines are still found in use for niche applications.
Generally, the volumes run on these machines tends to be low to moderate lot sizes of a few hundred to a few thousands of parts. With limited tool positions and availability of attachments, they are not ideal for complex or overly precise work. For the most part, the continued appeal of the machines is the low investment and the familiarity of a workforce with the older technology.
Tooling the machine does require designing special form tools for the job being produced, but with the low capital investment and spare parts readily available (though the machines are no longer produced), the Brown & Sharpe class screw machine can still be found in some US shops.
Though the US manufacturer, Brown & Sharpe, originated the design, European machine tools builders of Index, CVA, and BSA once produced very similar machines.
From 1950's and into the 1990's, Cox Manufacturing Company utilized the German counterparts to the Brown & Sharpe, Index-Werke. With the availability of a diversity of CNC models ideally suited for short run simple parts or high volume complex parts, Cox Manufacturing Company moved away from this technology to focus on more flexible, more accurate, and more cost effective total solutions.