Despite producing parts that are more expensive per unit, MIM tooling (molds) is typically cheaper than die casting tooling (dies). This surprises many engineers, but the reasons are grounded in the physics of each process.
Tooling cost comparison:| Tooling Element | MIM Mold | Die Casting Die | Why Die Casting Costs More |
|---|---|---|---|
| Typical cost | $8,000 - $30,000 | $10,000 - $60,000 | — |
| Steel type | H13, S136, NAK80 (pre-hardened or through-hardened) | H13, H11 (hot work tool steel), must withstand thermal shock | Die casting requires higher-grade hot work steel |
| Operating temperature | 40-120°C (mold temperature) | 200-350°C (die must stay hot to control solidification) | Thermal cycling fatigue drives steel quality requirements |
| Molten material temperature | 150-200°C (feedstock) | 400-700°C (zinc, aluminum, magnesium) | Higher temperatures = more thermal stress on die |
| Cooling system | Simple water channels | Complex conformal cooling required for uniform solidification | Casting requires precise thermal management |
| Expected life | 300k - 2M shots | 100k - 500k shots (aluminum); 500k - 2M (zinc) | Faster wear from thermal cycling and molten metal erosion |
MIM operates at 150-200°C (the temperature of the molten feedstock). The mold never experiences thermal shock because the temperatures are relatively low. Die casting operates at 600-700°C for aluminum — molten metal is injected into the die, and the surface of the die is heated and cooled with every shot. This thermal cycling causes heat checking (crazing) of the die surface, which limits die life and requires more expensive steel grades.
Quick Q: Why is MIM tooling cheaper than die casting tooling?MIM molds cost less because they operate at much lower temperatures (150-200°C vs 600-700°C for aluminum die casting). This means MIM molds can use simpler steels, less complex cooling systems, and have longer expected life (300k-2M shots vs 100k-500k for aluminum die casting). The lower thermal stress also means simpler maintenance and fewer repairs over the tool's life.