Die-Cast Quality, Without the Die – Rubber Plaster Mold Casting
[cite: 5]Rubber plaster mold casting delivers die-cast quality without the die-cast tooling cost[cite: 5]. It produces thin walls, crisp features, and fine surface finishes – matching many cosmetic and dimensional benefits of die casting – while using low-cost, flexible tooling that’s ideal for prototypes and short production runs[cite: 5]. That means you get near-die mechanical and aesthetic performance with much lower upfront investment and faster lead times than hard-tooling die cast methods[cite: 5].
See what other customers have to say about General Foundry Service →[cite: 5]Key Process Advantages
✓ Low-cost flexible tooling[cite: 5]
✓ Near-die mechanical & aesthetic performance[cite: 5]
✓ Ideal for prototypes & short runs[cite: 5]
✓ Reduced secondary machining[cite: 5]
Extremely thin-wall capability (down to ~0.080 in.) for lightweight, detailed parts, depending on geometry and alloy[cite: 5].
Superior as-cast surface finish (typical ~63 RMS) and sharper feature definition than sand methods[cite: 5].
High design freedom – fewer draft requirements and the ability to produce complex, deep-draw geometries[cite: 5].
Rapid validation of form, fit, and function with die-like appearance[cite: 5].
Lower tooling cost and faster lead time compared with die casting, ideal for validation, pilot runs, and limited production[cite: 5].
Precision execution tailored for complex requirements with minimal upfront investment[cite: 5].
Best For
Thin-wall, intricate, and highly detailed geometries with tight cosmetic requirements[cite: 5].
Volume Range
Low to low–mid volumes (prototypes to a few hundred/month)[cite: 5].
Surface Finish Need
High-quality as-cast surface suitable for cosmetic applications; often requires minimal finishing to achieve Class A appearance[cite: 5].
Medical and surgical instruments and housings
[cite: 5]Biotech and life science components
[cite: 5]Electronic enclosures and precision mechanical parts
[cite: 5]Robotic housings and ancillary hardware
[cite: 5]Non-structural aerospace components and pilot production parts
[cite: 5]Semiconductor and instrumentation components, and more[cite: 5]
- Produce master negatives from the pattern or prototype[cite: 5].
- Cast rubber against the masters and coreboxes to create flexible rubber positives[cite: 5].
- Pour plaster slurry against the rubber positives and coreboxes to form plaster mold halves and cores[cite: 5].
- Allow plaster to set and then bake molds and cores to achieve required strength[cite: 5].
- Assemble and pin mold halves; insert plaster cores for hollow features or undercuts[cite: 5].
- Pour molten metal into the plaster molds[cite: 5].
- Shake out and clean the castings[cite: 5].
Ready to accelerate your validation and lower program cost?
[cite: 5]Not sure which process is right for your part? With five casting processes under one roof, our engineers will evaluate your geometry and recommend the best fit — talk to an engineer today[cite: 5]. General Foundry Service pairs rubber plaster mold capability with in-house patternmaking and machining to deliver fully supported prototype and low-volume production programs[cite: 5].
Contact Us[cite: 5]