Both pressure and gravity die casting are effective methods for creating intricate metal components.

For those not familiar with metal casting, it may seem confusing as to what the difference between the two is, and which one would be most appropriate for your project.

Keep reading as we break down their key differences, such as their varied processes and applications, as well as how to decide which one you need.

What is the difference between pressure die casting and gravity die casting?

Die casting refers to a manufacturing process which involves manipulating molten metal into a mould to create a desired shape.

Pressure die casting and gravity die casting are both techniques used to create often complex parts for a wide range of industries, including but not limited to construction, lighting, and automotive.

With pressure die casting, molten metal is injected with force into a mould and compressed until the desired shape is formed, using huge amounts of pressure. Low-pressure die casting is another method which uses smaller amounts of force.

Alternatively, gravity die casting allows the metal to slowly take form in the mould, relying solely on gravity as a force of pressure.

Process

The die casting process typically follows these five stages:

Firstly, a mould, or die, must be designed to replicate the shape of the desired outcome.
Next, the molten metal is ejected into the die. For pressure die casting, this means that the metal is poured into the machine vertically, before being forced into the cavity using a high-pressure injection piston. When using gravity die casting, molten metal is poured into the mould from above at a controlled speed.
During the cooling stage, force must be continually applied until the metal becomes cool and solid if using high-pressure die-casting processes. For gravity die casting, the molten metal is left alone to slowly take the shape of the mould.
Components are carefully removed from their dies once solid.
Once completed, the product can be trimmed, sanded or painted for a desired finish.

Product Quality

Pressure die casting creates metal components with exceptional dimensional accuracy, perfect for a broad range of requirements. However, due to its manufacturing process, components can be porous and lacking in wall thickness.

With gravity die casting, this is avoided, resulting in high-quality castings that are much stronger and more durable.

Applications

Pressure die casting is an exceptional method for applications like:

Automotive castings (including structural bodywork or battery casings)
Plumbing parts
Kitchenware (pots and pans, cutlery)
Electronic components

Gravity die casting, however, is an outstanding method to create pieces such as:

Engineering and automotive parts that require more strength, like cylinder heads
Lighting fixtures
Medical devices, including casings

How do I know if I need pressure or gravity die casting?

If you require a die casting method that can keep up with high-volume production runs, a high-pressure method is typically the best option for you.

However, if you want a process that will reward you with strong, durable outcomes, gravity die casting may be worth considering.

If you’re still unsure whether a pressure or gravity die-cast would be best for you, at Lupton & Place we provide bespoke advice to our customers and can give tailored recommendations based on the information you give us.

Choose Lupton & Place for your Die Casting Products

Our team are here to support you at every step of your project – for more information regarding our products or other casting methods, contact one of our friendly specialists today!