Screw machines are automated lathes which can machine turned parts. The appellation “screw machine” might be slightly misleading, as they don’t actually screw anything in, nor do they necessarily thread materials, although this is one of their functions. Essentially, they machine components by spinning on a very quickly rotating lathe, which shaves metal down to a desired size.
There are two types of screw machines: Turret and Swiss machine. The Turret type, also called a Brown & Sharpe after its first manufacturer, mounts the workpiece on a vertical ram which works into the lathe. The Swiss type, named after its place of origin where watchmakers used it for precision components, mounts the work-piece on a rotary slide. While these two types function differently, their benefits and output are essentially the same, although the Swiss screw machine is better at more precise work.