Extruded Aluminum Heatsink vs Die-Cast Heatsink: Which Wins?

When you’re designing thermal solutions, choosing between extruded and die-cast aluminum heatsinks can be tricky. Both have benefits—but which suits your needs best?

Extrusion usually offers better thermal performance and flexibility at lower tooling cost, while die casting excels in shape complexity and volume production.

Let’s dig into performance, cost, production suitability, and manufacturing precision.

1. How Do Thermal Performance Results Differ?

Thermal performance hinges on conductivity, fin density, and airflow.

• Extruded heatsinks use alloys like 6063/6061 with thermal conductivity ~160–205?W/m·K .
• Die-casts often use ADC12/ZL102 alloys with lower conductivity (~120–155?W/m·K) .

Extrusions have clean, dense fins and no porosity—providing up to 23–53% better cooling than castings .

Thermal Comparison Table

2. What Are the Cost Implications?

Cost analysis includes tooling, unit price, and processing.

• Extrusion tooling: ~$5K–7.5K per die.
• Die casting tooling: $50K–100K+ molds, long lead times .
• Unit cost: Extrusions may need secondary machining—adding expense. Die cast can yield net-shape parts for less unit machining.

Cost Comparison Table

3. Which Suits Custom vs Mass Production?

Your production volume and shape complexity decide which process to use:

• Extrusion is ideal for custom profiles and medium volumes due to low tooling costs and fast turnaround (~2 weeks for dies) .
• Die casting fits high volumes and complex geometries, but entails long tooling (30–45 days) and higher upfront cost.

Production Suitability Table

4. How Do Manufacturing Tolerances Compare?

Accuracy matters when heatsinks must align with fasteners or electronic components:

• Die casting offers finer tolerances (CT4–CT5) and true net-shape output :contentReference[oaicite:8]{index=8}.
• Extrusion yields consistent cross-sections but needs secondary machining for tight features (~±0.2?mm typical) :contentReference[oaicite:9]{index=9}.

Tolerance Table

Summary Table

What Should You Choose?

• Pick extrusion if:

  • You need high thermal efficiency
  • Volume is low to medium
  • Simple fins with optional post-machining work
  • Faster and cheaper upfront tooling

• Pick die casting if:

  • You require intricate 3D shapes or integrated features
  • Volume is high (avoid costs of machining large numbers)
  • Precision and minimal post-processing are essential

• Hybrid design? Consider combining profiles with machined parts or bonded components for optimized function.

Quiz Yourself

Conclusion

• Extruded heatsinks deliver superior thermal performance, fast tooling, and flexibility—best for custom and medium-volume runs.
• Die-cast heatsinks excel in complex shapes and strict tolerances, and shine when producing large quantities.
• Choose based on thermal needs, design complexity, volume, and budget constraints—you’ll always find a clear winner for your project.

Need help evaluating a specific part or thermal load? Just share the details—I’ll help you pick the perfect solution.