(This post is a video that illustrates the typical spray nozzle arrangement for casting fan blades.)
From the die casting video published on Jul 9, 2013, "Die casting is a customized manufacturing method for producing OEM aluminum and zinc parts by forcing molten aluminum and zinc through high pressure into solid steel molds. These steel molds, called dies, are designed to create complicated layouts with a pinpoint accuracy and high volume production. Die cast parts can be precisely shaped, with rough or smooth material sides, and are optimized for a wide variety of attractive and serviceable finishes."
