Forged, Cast or Billet: what are the differences.

Forged, Cast and Billet are terms to describe alternative ways of producing metal components. To determine which process will be right for your project, you first need to understand the basics of what each process involves: how each of the parts is made, what it’s best used for, how it will perform, and what it’s likely to cost.

What is casting?

In the casting process, molten metal is poured into a mould. It then cools and solidifies into a component in the shape of the mould.

Gravity die casting

In Gravity Die Casting, molten metal is poured into a reusable metal mould and shaped to the mould by gravity. Offers better surface finish, higher strength than sand casting, with lower tooling costs than high-pressure die casting.

High-pressure die casting

In High Pressure Die Casting, molten metal is injected into a steel mould at high pressure, producing complex components with tight tolerances.

Sand casting

In Sand Casting, molten metal is poured into a mould made from tightly compacted sand, offering low tooling costs for manufacturing small or large components.

What is forging

Forging is the process whereby metal is heated until it becomes malleable, and is then shaped by being compressed. This produces metal components with high strength and toughness with excellent fatigue and impact resistance. When exceptional reliability is needed for critical loads. Also requires high tooling cost (dies and presses) offers less freedom for intricate shapes, and not cost-effective low-volume or highly detailed parts.

What is billet machining

A billet is a piece of raw metal cut from a solid block, then shaped by computer-controlled cutting tools into precise parts. These provide uniform, high-precision structures and tight tolerances requiring no expensive moulds. A disadvantage is that up to 70% of the billet may be cut away and discarded, while producing parts is slower, so unit cost are higher for large volumes.

Which is best for my project?

There’s no single best manufacturing method, as the right choice depends on what your component needs to do. When weighing up forged vs cast vs billet, consider the strength and durability the part requires, how complex its shape is, the level of precision and finish you need and how many units you plan to produce. Each process has clear strengths, so the guide below sets out when each one is likely to be the right fit for your project.

When to choose Billet

Billet is most suited to components needing precision, customisation and a well finished appearance, eg: brackets and machined components for aerospace, automotive and robotics; precision housings and mounting plates for electronics and instrumentation.

When to choose casting

Casting is used extensively for large, complex shapes and high-volume items, eg: engine blocks, transmission housings; consumer product housings, appliances, power tools, electronics; Industrial equipment: pumps, compressors, valve bodies,

When to choose forging

Forged is best when strength, impact resistance and fatigue life are important, eg: suspension components; engine components: connecting rods, high performing pistons; high-fatigue components: drive shafts, couplings, and crankshafts in heavy equipment.

Why choose Roston Castings

We’re a specialist aluminium prototype and gravity die casting foundry based in Derbyshire, UK. For over 60 years we have supplied high-quality aluminium castings for a wide range of technical applications and are trusted by leading manufacturers across automotive, aerospace, agriculture and engineering.

We produce high-performing die castings for a wide range of applications and industries. These offer an efficient, effective and affordable alternative to high-pressure casting, helping to save time and reduce costs on your next project.

We provide in-house CNC machining and toolmaking to support our casting service. This allows us to deliver a true end-to-end solution, removing the need for costly and time-consuming subcontracting while maintaining the quality standards we are known for at every stage.

If you’d like more information about Roston Castings, and would like to discuss a project and receive a quote, please get in touch.