 The dies are designed so that the finished casting will slide off the cover half of the die and stay in the ejector half as the dies are opened . This assures that the casting will be ejected every cycle because the ejector half contains the ejector pins to push the casting out of that die half . The ejector pins are driven by an ejector pin plate , which accurately drives all of the pins at the same time and with the same force , so that the casting is not damaged . The ejector pin plate also retracts the pins after ejecting the casting to prepare for the next shot . There must be enough ejector pins to keep the overall force on each pin low , because the casting is still hot and can be damaged by excessive force . The pins still leave a mark , so they must be located in places where these marks will not hamper the casting 's purpose . 
