Machining Deep Diecast Molds: How RHS Tooling Makes It Possible

When it comes to aluminum diecast mold making, most shops know it’s no walk in the park. Unlike plastic injection molds, diecast tooling involves molten aluminum, Dievar steel blocks, and deep, complex cavities that require both precision and durability. These types of jobs can wear down your tooling, consume too much machine time, and lead to unstable setups — especially when dealing with awkward angles or deep ribs. 

At Rapid Holding Systems, we recently worked on a challenging diecast mold project for a Canadian customer — and it was the perfect example of how the right workholding solutions can completely change your workflow. 

The Problem: Deep Cavities + High-Wear Steel 

This project involved machining Dievar steel blocks — a tough material chosen for its durability under extreme conditions like molten aluminum casting. The mold required deep cavities, tight tolerances, and side-mounted setups for boring mill operations. Conventional fixtures simply wouldn’t offer the stability or flexibility needed. 

The question was: 
How can we safely machine complex geometry into hardened steel blocks, without compromising precision or tool life? 

✅ The Solution: RHS Tooling for Deep and Rigid Setups 

Using Rapid Holding Systems tooling, we were able to set up, machine, and EDM burn this diecast mold block efficiently and precisely. 

Tools used in this project: 

1. 🔧 RHS EDM Extensions 
   These extensions allowed us to burn deep cavities that couldn’t be reached by standard tools. Built for Wire EDM and EDM burning operations, they’re rigid, precise, and designed for difficult geometries. 

2. 🧱 RHS U Holders 
   Our U Holders helped secure the graphite during EDM setup and ensured consistent positioning for critical dimensions. 

3. 🛠️ CNC Pull-Down Units 
   Compatible with FCS and Schunk-style systems, these pull-downs allowed us to side-mount the blocks on the boring mill. With M16 threaded screws and precision-ground spigots, the result was a rigid and accurate setup that could handle both vertical and horizontal machining. 

💡 Why It Matters for Other Machinists 

Whether you’re machining plastic molds, aluminum diecast cores, or high-precision steel components, the right workholding system can save hours of setup time and prevent costly errors. 

By integrating modular EDM extensions, precise U holders, and rigid pull-down clamping systems, your shop can: 

• ✅ Eliminate vibration and deflection during deep cavity machining 

• ✅ Speed up changeovers between setups 

• ✅ Improve repeatability and reduce scrap 

• ✅ Handle tougher jobs with more confidence 

Ready to Upgrade Your Diecast or EDM Setup? 

This project is just one example of how Rapid Holding Systems tools are helping moldmakers, machinists, and manufacturers across North America solve real-world challenges on the shop floor. 

If you’re tackling deep cavity EDM burns, complex diecast molds, or want better setups for your CNC boring mill — we’ve got your back. 

📩 Contact us today to find the right solution for your next job: 
👉 [email protected] 
🌐 rapidholdingsystems.com