Ring rolling is a specialized type of metal forming operation, which reduces the thickness (cross section) and enlarges the diameter (circumference) of the work piece by a squeezing action as it passes between two rotating rollers.
Rolling (metal working), In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rollers to reduce the thickness and to make the thickness uniform.
The production of seamless forged rings is often performed by a process called ring rolling on rollingmills. The process starts with a circular preform of metal that has been previously upset and pierced (using the open die forging process) to form a hollow “doughnut.”
Producing a thin, large-diameter ring from a thicker, smaller-diameter ring by placing the ring between two rotating rollers.