What Are the Different Parts of a Die-Casting Mold? A Practical Guide for Designers

Die-casting molds—also called dies—are the heart of the high-pressure die casting process. A well-designed mold not only determines the shape and accuracy of the part, but also impacts cycle time, surface finish, and tool life. Understanding the core components of a die is essential, especially for product designers and sourcing professionals involved in DFM (Design for Manufacturability).

Here’s a breakdown of the main elements of a typical die-casting mold:

1. Cavity & Core Inserts

   These form the external and internal geometry of the part, respectively. They’re typically made from H13 or other tool steels and are the first to wear due to direct contact with molten metal.

2. Die Blocks (Fixed & Moving Halves)

   The mold is split into a stationary (cover) and moving (ejector) side. Each half is mounted to the platens of the die-casting machine and holds the cavity and core inserts in position.

3. Ejector Pins

   Once the part solidifies, these pins push the casting out of the mold. Proper ejector layout avoids deformation and sticking.

4. Sprue, Runner, and Gate System

   This network channels molten metal from the injection sleeve into the cavity. Gate design influences metal flow, filling speed, and final part integrity.

5. Vents and Vacuum Channels

   Trapped air must be evacuated quickly—vents allow gases to escape, while vacuum-assisted systems are used in more advanced molds for critical parts.

6. Cooling Channels

   Water or oil flows through these passages to regulate die temperature, which is critical for dimensional consistency and reduced cycle time.

   
   

At LVIO Precision, we work closely with tooling partners and customers to ensure each mold is optimized not just for geometry, but also for casting efficiency and longevity. Our DFM input helps reduce part defects and tooling cost over the product’s lifespan.

Ready to start tooling design for your next die-cast part? Talk to us early—we can help you get it right from the start.