Gravity die casting for strong, pressure-tight aluminium parts.

Gravity die casting, also called permanent mould casting, fills a reusable metal mould under gravity rather than high pressure. It's chosen for aluminium parts where mechanical strength and pressure-tightness matter more than cycle time: housings, brackets and structural components. Solstice sources gravity castings through audited Far East partner foundries, machines them to your drawing and manages the whole job from the UK.

When to choose it

When gravity die casting is the right choice

Strength

Slower, calmer filling gives a denser casting with fewer gas voids than HPDC.

Pressure-tightness

Well suited to housings and parts that carry fluids or gases.

Heat treatment

Gravity castings can usually be heat treated (e.g. T6) for extra strength.

Medium volumes

Tooling generally costs less than HPDC, so it suits lower annual quantities.

Thicker sections and cored features

Sand cores can form internal passages.

Gravity die casting at a glance

Material

Aluminium

Part weight

< 50 g – 15 kg

Tooling

New build or existing tool transfer

Volumes

Prototype through to series production

Testing

Leak/pressure testing available

Delivered

CNC machined and finished to print, on a UK invoice

Comparison

Gravity vs high pressure

HPDC wins on cycle time, thin walls and as-cast finish at high volume. Gravity wins on strength, density and pressure-tightness. If you're unsure which suits your part, send the drawing and we'll recommend one. See high pressure die casting.

Process

Cast, then machined

Flange faces machined flat, bores and ports finished to size, mounting holes drilled and tapped to print, all as part of the same production run. Leak and pressure testing, shot blasting, powder coating and sub-assembly can be included, so parts arrive ready to fit.

Gravity die cast aluminium flanged housing, CNC machined flange faces and bore

Materials & parts

Materials and typical parts

Materials

Aluminium alloys, e.g. LM25 / A356 equivalents.

Typical parts

Pump and valve bodies, manifolds, structural brackets, motor housings and fluid-carrying housings.

FAQ

Common questions

Is gravity die casting the same as permanent mould casting?

Yes. Both terms describe pouring metal into a reusable metal mould under gravity.

Can you leak test the parts?

Yes. Leak and pressure testing can be built into the order for sealed housings and fluid-carrying parts.

What do I need to get a quote?

A 2D or 3D drawing, annual volume and finish requirements. A sample part works too.