China United Mould

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CNC Machining of Die Castings

Machining

CNC machining that respects the casting

Die castings are near net shape, but sealing faces, bearing bores, threads and tight-tolerance features are usually machined. Three things decide whether this goes smoothly: datums that cast consistently, a small machining allowance (typically a few tenths of a millimeter up to about 1 mm), and machined faces kept out of thick, porosity-prone sections. The dense skin of a die casting is only a fraction of a millimeter deep, so heavy cuts tend to open porosity.

We machine castings on CNC with fixtures made for each part and check machined features against your drawing.

CNC machining of aluminum die cast housings
Dimensional inspection of a machined aluminum die casting

Typical machining on castings

Machining FAQ

How much machining allowance does a die casting need?

Typically a few tenths of a millimeter up to about 1 mm, depending on part size and the feature. More allowance cuts through the dense surface skin and can expose porosity.

Why can machining expose porosity?

The skin of a die casting is dense, while thick sections can hold gas or shrinkage porosity. Uniform walls and small machining allowances keep machined surfaces sound.

Have a casting to quote? Tell us the part, the alloy and the annual volume.