Converting from Billet to Forged Aluminum
Anchor Harvey is proud to provide a wide variety of custom forged aluminum products, but customers may wonder why they may need forged products instead of billeted material products. What are billets, what is billeting, and what’s the difference between billet and forged products? And when it comes to billet aluminum versus forged parts, which is superior?
The following will provide you with an understanding of the billeting process, the advantages and disadvantages of aluminum billet vs. forged aluminum, and why you should choose the custom forged aluminum products from Anchor Harvey.
What is Forging?
Forging is the process of using pressure and heat to form metal to a specific end shape. This can include the use of large hammers to strike a stock material against an open die, a large, heavy press to slowly shape a material against a closed or open die, or a belt or press forcing material through heavy rollers that reduce and shape the metal. In the case of forging versus billeting, the process of forging will generally mean forging the part to its final shape or close to its final shape.
What is a Billet?
A billet is a long, shaped bar of metal. Billet is technically not a forming process, and aluminum billets can actually be formed through extrusion, roll forging, or can even be cast. Billets will often be formed through roll forging by passing stock through two heavy steel rollers that form it to specific shape parameters. Forged billet aluminum is a high-quality stock material for many post-forging processes.
Billeting refers to the process of forming a billet. However, an aluminum billet is primarily considered a stock material for further forming processes. The most common use cases for billets are as feeder material to machining processes. Machining is the generic name of a huge variety of metal cutting processes that use special cutting tools and powerful machines to remove material from stock pieces and produce incredibly precise final parts. Billeting and machining can produce the most precise parts possible, and certain electric discharge machining processes can produce parts with tolerances within 1-2 microns. The obvious gains from this kind of precision are sometimes necessary for the most precise parts that require that kind of exact measurements.
Billet and machining can be used to produce micro-features that are simply impossible with other forms of metal forming. Specific forms of high-speed machining, electro-discharge wire cutting, and surface precision grinding can produce parts with textures that would become completely lost in the heating and cooling process of forging.
Billet vs. Forged
Considering the benefits of each, and weighing the pros and cons of billet vs. forged, why should a customer choose a custom forging over an aluminum billet and machining process? There are a few key differences between the billet and forging processes that make the choice of a custom forging a more desirable option for most industries.
- Cost vs. Necessary Dimensions: Machining aluminum billets is a costly procedure, especially for some of the tightest tolerances. However, many applications don’t require the kind of tolerances and precision that machining can produce. This translates to a lower cost for forging in most cases. Simply put, machining is unnecessary for industrial applications.
- Strength: A fully formed forging shaped to the end product is ultimately stronger than a billet machined to shape. The natural internal stresses produced through the forging process create a product with a grain structure that wraps in a natural way. Machining, by its nature, cuts through the grain structure of a billet. This opens up the internal structure and lowers the overall strength. This can be alleviated somewhat by heat treatment, but that also adds cost and cannot recreate the overall strength of a hot worked forging.
- Scalability: Machining is a long process that cannot approach the throughput of a forging shop. While certain simple machining processes are faster than others, the cost of each new part scales linearly because each part needs to be loaded into a machine separately and run through a possibly quite lengthy machining program. This can work for certain low-volume orders but becomes prohibitively expensive at the scales at which many modern manufacturers operate.
When the question of comparing billet aluminum and forged aluminum parts comes up, it’s important for manufacturers to know what each half of the ‘billet vs. forged’ argument really means. Billeting is ultimately an intermediary step and requires extra work at a machine shop to acquire a finished product.
Anchor Harvey can produce high-quality forged aluminum products custom shaped to the customer’s needs with faster turnarounds and precision necessary for aerospace and many other industries. Request a quote today.