For most manufacturers, the ideal production process is one where the required part is created in a single operation with no machining needed.
Unfortunately, that’s seldom possible when working with metal, and that’s because demanding tolerances, precise surface finishes, and complex part geometries mean that some metal removal is almost always needed.
Near-net shape manufacturing, a technique where the initial production of a part is close to the final (net) shape, was designed to help to overcome the challenges of waste in metalworking.
Impression die forging is one such process, and it comes with significant advantages compared to other near-net methods:
Dimensional Consistency
Impression die forging is a highly repeatable process. The geometry of the final product is determined by cavities machined in the two halves of the die, and these are closely matched for accurate alignment. The hot billet or preform is placed between the two halves, which close under high pressure. Excess material emerges from between the two halves as flash, which is subsequently trimmed away.
The resulting part-to-part and batch-to-batch consistency simplifies secondary machining operations, as there is minimal variation to deal with. It also helps ensure a good fit when the part is installed in a final assembly, as well as consistency in part mass, which is especially important in automotive and other transportation applications.
Minimal Secondary Machining Needed
Despite the impressive speed and capabilities of modern CNC machine tools, machining is still a slow, expensive, and wasteful process.
With a near-net process like impression die forging, the volume of metal that needs to be removed is reduced, so less part finishing work is needed. This translates to higher cost savings and faster lead times, especially when compared to machining a complex part from a solid billet.
Higher Production Rates
Machining from solid billet is a laborious process: solid material is cut to the overall size, and then painstakingly machined through multiple machines and operations. Casting is better, as less machining is needed, but still requires considerable time for melting, pouring, and solidification, plus all the various QC checks to ensure quality and consistency.
In contrast, impression die forging is quick; it takes just seconds to turn a cut piece into a near-net shape part. Keep in mind that preheating is still needed, but can be done quickly in a batch or continuous oven.
The reduction in secondary machining also saves time, as does the elimination of handling operations between machine tools. Put these together, and it’s clear that forging allows for higher production rates and faster delivery.
Less Waste
Machining is inherently wasteful. Resources are consumed to remove material from the part the customer wants. If the part can be produced without that excess material, fewer resources are needed and there is less waste.
In addition to the machine time, power consumption, and material handling, machining generates waste chips. Chips are a big problem because they require costly and careful disposal. Actions to reduce chip costs, like segregating different types of material and installing minimum quantity lubrication systems, all carry costs, too.
The waste produced by CNC machines also means that regular cleaning is required; chips that are left in the machine impact accuracy, can damage seals and wipers, and create unnecessary safety risks.
Comparatively, impression die forging does not produce as much waste. Although it’s still impossible to eliminate scrap, that scrap can be transformed back into raw material and used again to produce more forgings, which is exactly what Trenton Forging does.
Cost-Effective Tooling Design
Like other near-net shape manufacturing processes, impression die forging requires tooling. This carries a cost, which in turn means that for very small quantities, machining from solid can be less expensive.
However, depending on part geometry, the quantity at which forging becomes the less expensive process can be surprisingly low.
Specifically, it’s possible to take laser scans of an existing part, import the data into CAD, and generate accurate 2D drawings and 3D parametric models. Products like AutoCAD, Solid Works, and Creo Elements give tool designers the ability to quickly create die designs from these, or from customer-supplied prints. Drawings can then quickly be transferred to CAM programs, and from there, to the CNC machine tools. Keep in mind that these benefits are maximized when the forging company offers tool design and manufacture in-house.
Let Trenton Forging Support Your Next Project
Trenton Forging has been an industry-leading manufacturer for over 50 years, and there’s a reason for it: our commitment to integrity, innovation, urgency, and engineering excellence.
Since our founding, we’ve specialized in producing symmetrical and asymmetrical forgings for safety-critical applications. Other value-added services we offer include design and engineering consultations, in-house tooling, and 3D laser scanning and reverse engineering.
Trenton is a forging company that’s intensely focused on meeting customer needs. This means striving for engineering excellence and robust quality, while also ensuring integrity, innovation, and urgency.
If you have a part that needs forging, and you’d like a quote or a first article sample, contact us today to get started.
