Forging vs Casting: The Age-Old Question “When do you choose a Forging or a Casting”
(A guide for the metals industry professional responsible for sourcing metal parts.)
Article 1:1 An Introduction into Sourcing Metal Parts
Forging vs Casting? How to decide? Although the answer to forging vs casting is clear to us “gray haired metallurgists”, it is important to realize that new people enter the metals industry every day and may not have been exposed to some of the basics.
You can make informed decisions. Nobody should feel ashamed or uninformed because they ask the question about forging vs casting. In fact, sometimes there is no “correct answer” to the question of forging vs casting. Metalworking technology evolves and improves every year. It is important to stay informed about metal technology.
The reason to choose one metalworking technology over another depends on the environment in which the metal part will be used. In general, if the part will be subject to high service loads and cyclic stresses, a forging will always be “better performing” than a casting given the same material and service conditions.
The reason why a forging is “better” than a casting will be explained in future articles. However, there are many valid reasons to choose a casting over a forging for many applications. If you are a purchasing professional, listen to your engineering staff about how to source your parts. If you are an engineer who is advising your purchasing department about sourcing parts, you should discuss all aspects of your design, including “cost”, with your purchasing department.
Choosing one metal process over another comes down to metallurgy and economics. Be aware of the “total cost” of the part because it will have a huge impact on profitability. You must investigate all the “downstream” processes such as heat treatment, machining and finishing operations to determine total cost. As an engineer, it is your responsibility to look at total cost of specifying a process (forging vs casting). This will help your company by choosing the process that will meet your design needs at the lowest possible cost.
The next article will address the technical and commercial reasons as to why one process may be better suited than another to meet your needs.
GPi Metal Products, LLC