MACHINABILITY

Another of the valuable properties of brass and bronze casting alloys is their exceIlent machinability.
Lead is present in many copper casting alloys. usually as fine(y divided particles which serve to break up chips when the metal is machined. Most of the leaded brasses and bronzes are thus considered "free-machining."
Because of their. good machinability. these leaded aDoys lend themselves well to modern high-speed productton methods. Millions of copper alloy castings are machined each year OD turrec lathes, automatic screw machines and other mgh-speed production devices. In many cases the ability to machine at high speed is the chief factor in the. selection of a copper alloy for a particular application.
Even the high-strength copper alloys that do not contain lead usually have much better than avemge machining properties.