Hubbing is a metalworking

Metalworking

Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. It therefore includes a correspondingly wide range of skills,...

 process that is used to make die

Die (manufacturing)

A die is a specialized tool used in manufacturing industries to cut or shape material using a press. Like molds, dies are generally customized to the item they are used to create...

s. It is a cold-working process, which means that it occurs well below the melting temperature of the metal being worked.

Process

In hubbing, a male hub (master) is created with a profile that will form an impression on the female piece. The male hub is generally hardened and the female die block softened by annealing to help form the impression. As the metal flows the face of the die block is deformed, and, generally, must be machined flat. The die block is often a cylinder that is reinforced with a surrounding steel ring during the hubbing process. Hubbing is usually less expensive than die sinking, i.e., machining the female die, and multiple dies can be made from the male hub.

A hubbing press exerts a pressure of approximately 1500 short ton

Short ton

The short ton is a unit of mass equal to . In the United States it is often called simply ton without distinguishing it from the metric ton or the long ton ; rather, the other two are specifically noted. There are, however, some U.S...

s-force per square inch (21 GPa) to transfer the image from a master hub into the master die.