Electrical Discharge Machining (EDM) vs. High-Speed Milling for Injection Mold Tools

Injection mold tools are crucial for manufacturing plastic parts, and achieving precision and efficiency in their production is vital for successful molding. Two common methods for making these tools are Electrical Discharge Machining (EDM) and High-Speed Milling. Understanding the differences between these methods and knowing when to use each one is key to optimizing the manufacturing process and achieving high-quality mold tools. Today’s technical post explores these techniques in detail.

EDM is a non-traditional machining process that uses electrical discharges to remove material from the workpiece. It is particularly well-suited for intricate geometries, hard materials, and tight tolerance requirements. EDM can achieve high precision and surface finish quality, making it ideal for producing complex features, fine details, and cavities in injection mold tools that may be challenging to achieve using conventional machining methods. However, EDM is a slower process compared to milling and may not be as cost-effective for removing large volumes of material.

On the other hand, High-Speed Milling is a conventional machining technique that uses rotary cutting tools to remove material from the workpiece at higher speeds and feeds than traditional milling processes. High-Speed Milling is suitable for roughing and semi-finishing operations, as it offers faster material removal rates and shorter lead times compared to EDM. High-Speed Milling is well-suited for producing injection mold tools with larger dimensions, simpler geometries, and when a faster turnaround time is required.

EDM is best used to produce features with intricate geometries, fine details and complex features. It is also useful working with hard materials that are difficult to machine using conventional methods. When high precision and excellent surface finish quality is required, EDM is often selected as the optimal manufacturing method.

High-speed milling is used to remove larger volumes of material efficiently and quickly. When molds require simpler geometries and larger dimensions, high speed milling is often used to “rough out” larger amounts of bulk material from a mold base. High-speed milling provides faster turnaround times and may be used to expedite the machining process. Smaller cutting tools can be applied to further refine features and surfaces, after the majority of material is cut away from the mold.

In conclusion, the choice between EDM and High-Speed Milling for manufacturing injection mold tools depends on the specific requirements of the mold design, material properties, desired surface finish, and production timelines. PDC understands the strengths and limitations of each method and considers the factors influencing the manufacturing process. This enables PDC to help customers make informed decisions to optimize the production of high-quality mold tools for plastic injection molding applications.