Die Casting


►Major Die Components


Casting dies have many components. The mold base is the steel envelope that is

designed to hold all the other die components together. It is split or parted into

two halves, " stationary (cover ) " and " moving ( Ejector ) ". This split is known

as the parting line.

The stationary half mold base :

It has a number of components and features that are important to the die's function.

♦1. Its most important function is to act as a container for the stationary die cavities.

♦2. It provides a means for attaching the stationary die half to the machine.

♦3. It couples the injection system of machine to the die.

♦4. It provides a means for aligning to two die halves.

Ejector pins :

Ejector pins extend from the ejector plate to the casting. They leave marks on the

casting These ejector pin marks may vary in height, with respect to the adjacent 

casting surface.

♦1. If the ejector pin is too long, it will leave an indentation that may make it difficult to

remove the casting from the die.

♦2. If the ejector pin is too short, it will leave a raised boss on the casting that may be


Core pins :

Core  pins are similar to ejector pins, however their size tolerance are slightly different.

Core pins are usually to cast round holes in the part, but their shape is not restricted to

being round, only the core pin body must be round. Core pins can be very fragile and fail

if not taken care of. They must be sprayed with die release in order to prevent the build-

up solder.

Slides :

Sometimes features are cast that can't be created with the normal opening and closing

of the die. This can be done with a component called a " slide " The motion of a slide is

in a direction different than normal opening and closing. A cavity feature can be

mounted on a slide, and then this slide is withdrawn  from the casting before

casting is ejected. If the slide is mounted in the stationary die half, then

the slide must be withdrawn before DCM opens the die.

The slides may be actuated either with a hydraulic cylinder.