Injection molding is a very basic tool used to design products. Every Mechanical Designer Should be familiar with the basics. The process of injection moulding or molding is very simple. Imagine if you took a big block of material and cored/emptied out the inside leaving one hole to the outside. When you fill it with hot plastic, the plastic will fill any area that is empty. Voila, You have yourself a plastic part. Of course, to be useful, you would have to find a way to take the plastic part out and that is how injection molding was born. The “big block” is actually made out of two separate blocks that join together to make the “cavity” or hole. When you are ready to take the plastic part out, you just need to open the two blocks and retrieve the part. This process can be highly automated and fast hence why small plastic parts are really cheap. The two blocks have names. One is a core and one is a Cavity. Feeling smarter already?