An injection mold is comprised of several key components. While the number of parts may vary due to complexity, a general breakdown includes:

1. Cavity and Core: These are the main parts that actually shape the plastic into the desired form. The cavity is the empty space that corresponds to the shape of the final product, while the core is the part that goes inside the cavity to form hollow spaces if needed.
2. Mold Base: This serves as the backbone of the mold, supporting all other components. It also acts as a passage for cooling/fluid channels.
3. Sprue, Runner, and Gate: These parts form the path through which the molten plastic flows into the cavity. The sprue is the primary channel that connects the injection nozzle with the runners, the runners distribute the plastic to different cavities, and the gate is the last passage before the plastic enters the cavity.
4. Ejector System: This includes ejector pins and the ejector retainer plate. Once the plastic part has cooled and solidified, the ejector system pushes the finalized part out of the cavity.
5. Cooling Channels: These are hollow channels within the mold for circulating coolant (usually water) to regulate the temperature of the mold, which affects cycle times and part quality.
6. Venting System: This allows air to escape from the mold cavity during the injection process.
7. Alignment System: These consist of guide pins, bushings, and other components that ensure the core and cavity align correctly every time the mold closes.