Forging is a process that shapes and moulds a piece of metal into the desired shape.
Another method of doing this is called casting, however, it is a very different process to forging. Casting is manufactured by pouring liquid metal into a mould, the hot liquid will then fill the desired shape and solidify.
Forging is an industry that is used worldwide, with some forging still being done by hand but most nowadays is manipulated into the required shapes by many different tools.
There are many different types of casting such as die-casting, plaster casting, sand casting and investment casting. Each one of these processes provides their own benefits.
Like casting there are many different types of forging, including hot and cold forging, open die forging, impression dies forging and seamless rolled ring forging.
The main types are hot and cold forging, the difference between these two processes are:
Cold Forging: this process increases the strength of the metal, by forging at room temperature.
Hot forging: this process is better for producing optimum strength high ductility and low hardness.
Whichever process of forging you use, there are common defects that can occur such as:
Cold shut: This can cause small cracks in the corners.
Unfilled Section: a section that does not fill
Improper grain growth
An old school blacksmith will usually carry out forging by hand, he will use tools or a steam-hammer to help him forge the metals into the desired shape.
The only metal that cannot be forged is cast iron because the carbon content is over 2% so it has a low melting point and is very brittle so cannot be used for forging.