Open Die Forging

The metal being shaped during open die forging is not completely confined during the process, which derives the name open die forging. Open die forging uses hammers and presses to shape metal parts anywhere from 5 to 500,000 lbs.

The open die forging process allows for some irregularities between forgings. The metal is usually rough machined and then finish machined to achieve final dimensions.

The metal used in open die forging may be heated to above recrystallization temperature and then reheated several times before the final product is achieved.

Impression Die Forging
In impression die forging, two dies are brought together, squeezing the metal causing it to fill the die impression. Depending on the design, metal can be allowed to flow outside of the dies or can be allotted no escape. The impression die forging process usually requires one hit through a die cavity for the metal.

The impression die forging process relies heavily on the work of the dies and less on the work of the operator.

Ring-Rolling
Ring rolling is a highly engineered process resulting in seamless rings or forgings. The rings can be produced on a variety of pieces of equipment, all of which produce a seamless section with a circumferential grain orientation. Ring-rolling offers a cost savings over closed-die processes.

Extrusion
Extrusion occurs when a container is filled with the source material that is then forced by pressure into an orifice. The process can occur in forward or in reverse depending on requirements for the finished product.

The final product of extrusion can be either solid or hollow.

Piercing
The process of piercing is similar to that of reverse extrusion. The main difference is that there is greater movement of the punch in comparison to the workpiece material.

Secondary Processes
In many instances after the initial forging process is concluded, secondary processes are implemented to change the condition of the forgings. Secondary processes include, heat treating, machining, plating, painting, drilling, welding and otherwise fabricating.