die-cast vs extruded aluminum: Complete Comparison

压铸铝与挤压铝：完整对比

Head-to-Head Comparison

Detailed Analysis

1. Performance

Let's start with thermal management—the single biggest factor in LED lifespan. Extruded 6063-T5 aluminum has a thermal conductivity of 150–200 W/m·K, per EN 755-2. Die-cast A380 sits at 96–120 W/m·K. That's a 35–40% difference. For a 100W LED driver running at 85°C junction temperature, an extruded heat sink can drop that to 75°C, which per the Arrhenius model doubles the driver's life from 50,000 to 100,000 hours. I've seen this on the bench—it's not theoretical.

But die-cast isn't a slouch on strength. A380 hits 310–330 MPa tensile strength, versus 180–240 MPa for 6063-T5. That matters when you're mounting a 15 kg floodlight on a pole in a high-wind zone. The catch: die-cast parts are brittle under impact. Drop a die-cast housing from 2 m onto concrete, and you'll likely see cracking along the gate lines. Extruded aluminum bends before it breaks—it's more forgiving on a job site.

What about lumen depreciation? Both materials perform similarly if the thermal path is designed right. But in practice, extruded heat sinks with fins spaced at 8–10 mm and 3 mm thickness dissipate heat 15–20% more efficiently than equivalent die-cast designs, per CIE 127:2007 testing. That translates to 5–8% less L70 depreciation over 50,000 hours. Bottom line: for high-power LEDs (>50W), extruded wins every time.

2. Cost Analysis

Upfront tooling is where the gap widens. A die-cast mold for a complex floodlight housing runs $15,000–$50,000. An extrusion die for a linear profile is $2,000–$8,000. For a run of 5,000 units, that's $3–$10 per part in tooling amortization for die-cast versus $0.40–$1.60 for extruded. You'll feel that in your P&L.

Unit cost flips at volume. At 10,000 pieces, die-cast A380 costs $4.50–$8.00 per kg, while extruded 6063 is $3.00–$5.50 per kg. But here's the thing: extruded profiles often require secondary machining for end caps, mounting brackets, and driver compartments—add $0.50–$2.00 per part. Die-cast can integrate those features in one shot. I've seen projects where die-cast was cheaper at 20,000+ units because it eliminated 3 assembly steps. Do the math on your specific BOM.

3. Application Suitability

Extruded aluminum dominates linear lighting—think 4-foot troffers, linear high bays, and track systems. The constant cross-section allows for continuous heat sink fins, and you can cut profiles to any length on site. Die-cast can't do that; you're stuck with the mold length.

Die-cast shines in 3D geometries. Need a junction box with integrated cable glands, a mounting arm, and a curved housing? Die-cast does it in one piece. Extruded would require welding or bolting multiple profiles, which adds cost and failure points. For outdoor floodlights with IP66 ratings, die-cast's ability to form complex sealing surfaces is a real advantage.

What about thermal performance in real-world conditions? For a 150W LED high bay running at 40°C ambient, an extruded heat sink with 12 fins (25 mm height, 3 mm thickness) keeps the junction at 72°C. A die-cast equivalent with the same volume hits 82°C. That's a 10°C difference—enough to push the LED driver past its 85°C rated limit on a hot day. I've replaced die-cast housings on warehouse jobs for exactly this reason.

4. Pros & Cons

Die-Cast Pros: Complex shapes in one shot, high strength (310+ MPa), thin walls down to 1.5 mm, excellent for sealed enclosures. Cons: Lower thermal conductivity (96–120 W/m·K), high tooling cost, brittle under impact, limited to mold size.

Extruded Pros: Superior thermal performance (150–200 W/m·K), low tooling cost, unlimited length, recyclable without coating, ductile. Cons: Constant cross-section only, lower strength (180–240 MPa), requires secondary operations for complex features.

Best Use Cases

Final Recommendation