Special features of die-castings

Of all the methods used in manufacturing, die-casting represents the shortest route from molten metal to finished part. To take greatest 

The sections of a die-casting should always be as uniform as possible - sudden changes of section affect the metal flow and lead to unsound areas of the casting. Differences in the rate of cooling between thick and thin sections produce uneven shrinkage, causing distortion and stress concentrations. 

Bosses are sometimes required to accommodate screws, studs, pins, etc. and, if designed with a section thicker than an adjacent thin wall, will also cause unequal shrinkage. This can be minimised by making the variation in thickness as small and as gradual as conditions permit. 

The die parting is the plane through which the two halves of the die separate to open and close. 

It is usually across the maximum dimension. The designer should visualise the casting in the die and design a shape which will be easy to remove. When the two die halves are closed, there is always a small gap at the two faces, into which metal will find its way due to pressure on the metal. This results in a small ragged edge of metal known as a flash, which has subsequently to be removed, usually by means of a trimming tool. The position of the flash has to be arranged so 

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