Mould Components and Terms

In the die-casting industry, there must be moulds. The mould is also has many parts, including cavities (or cavity inserts), parting lines, cores or core pins, slides or slide cores, ejector plates and ejector pins. Below I will give a brief introduction to each part.

Cavity Blocks or Cavity Inserts

These are the parts of the die casting mould that form the geometry of the part. Cavity blocks include ejector cavity and the cover cavity. Ejector cavity sometimes called the core cavity. The cavity blocks are made by high quality tool steel and it is usually heat treated to extremely high hardness. Then lubricate to maintain a long life. The water cooling line will pass through the cavity blocks, and the ejector pins used to push the parts out of the mold will also pass through the cavity blocks. The cavity blocks are very expensive because they need more design, engineering and detailed machining.

Parting Lines

The steps of manufacturing parts are: first, close the two mold halves, then inject metal into the cavity block, and after cooling, the parts can be taken out. So on the parts, the place where the cover half meets the ejector half will form a line, called the “parting line”.

Cores or Core Pins

A “core” is the part that forms the internal features of the casting. It is an independent and replaceable component. The core can be of any shape. Circular is a common shape of core and it also called as “core pin”. The core may be fixed to the mold cavity or slide block, mechanically opened/closed by the mold, or actuated by a hydraulic cylinder or other ways.

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