Gravity die casting for repeat aluminium parts
In gravity die casting the metal is poured into a permanent steel mould rather than a sand one, under gravity alone. The mould is reused thousands of times, so every casting comes out the same, with a smoother surface and tighter dimensions than sand can hold.
What you get over sand casting
The difference shows up in the machine shop and in your inspection report:
- A smoother as-cast surface, so less dressing and less machining stock
- Closer, more repeatable dimensions from piece to piece
- A finer grain structure as the metal cools faster against steel
- Lower cost per piece once the quantity covers the die
When it is worth the tooling
A die is a one-time cost that belongs to your job. It makes sense when the part repeats: a regular monthly or annual order, rather than a single replacement. For one-offs and short runs, sand casting is almost always the cheaper answer, and we will tell you so rather than sell you a die you do not need.
What suits a die
Aluminium parts with reasonably simple internal shapes: covers, housings, brackets, plates and similar components. Deep undercuts and complex internal passages are usually better in sand, where a core can be broken out afterwards.
How a die job starts
Send the drawing or the sample with your expected annual quantity. We will quote the die separately from the piece price, so you can see the payback and decide for yourself.
Questions customers ask
How is this different from pressure die casting?
Pressure die casting forces metal into the die with a ram at high pressure, which needs a much bigger machine and far higher tooling cost. Gravity die casting fills the mould under its own weight. For the quantities most of our customers order, gravity is the sensible middle ground between sand and pressure. We do not run pressure die casting here; it can be arranged with a partner foundry if your part truly needs it.
Who owns the die?
Agree it in writing at the start. Normally the die stays with us, stored and maintained for your repeat orders. If you want to own it outright, say so when you ask for the quotation.
What quantity makes a die worthwhile?
It depends on the part's size and the machining it would otherwise need. Send the drawing and your annual quantity and we will work out both options and show you the numbers.
Tell us what you need made.
A drawing, a CAD file or a worn sample part is enough to start. We are in Korangi, Karachi, and we answer on WhatsApp.