Aluminum alloy selection is not just a technical decision—it directly affects cost, part quality, and long-term performance. After more than 20 years in the die-casting business, we’ve seen how the wrong alloy can ruin a project before the first mold even closes.
This article is written for buyers and project managers who want to choose the right material for their aluminum die-cast parts—without getting lost in engineering jargon.
Why Alloy Selection Matters in Die Casting
At our factory, we always say: “Good tooling and process can’t fix a bad material choice.” Whether you’re making truck parts or consumer devices, the aluminum alloy you select determines how the molten metal flows, cools, fills the mold, and survives in the real world. Choosing the right alloy early helps reduce defects like porosity, shrinkage, and warping—and saves a lot of post-processing headaches later.
What Are the Most Common Aluminum Alloys in Die Casting?
Here are the most frequently used aluminum alloys we work with at Yongzhu Casting, and what they’re good for:
- ADC12 (JIS spec): Highly castable and cost-efficient. Ideal for general-purpose parts.
- A380 (ASTM spec): Balanced properties, good for North American clients with UL or automotive standards.
- EN AC-46000 (AlSi9Cu3): Common in Europe, good for general parts, decent strength and corrosion resistance.
- B390: Very hard, great for wear-resistant parts like automotive cylinder liners, but brittle and hard to machine.
- A356 / A319: For heat-treatable jobs, often used in structural and high-performance parts.
Each alloy has trade-offs. The best one depends on what your parts actually do—not just what’s listed in a spec sheet.
Alloy Comparison Table: Properties at a Glance
Here’s a quick side-by-side summary of the most requested alloys in our orders:
| Alloy | Castability | Tensile Strength (MPa) | Elongation (%) | Machinability | Typical Use Case |
|---|---|---|---|---|---|
| ADC12 | Excellent | 310–330 | 1.5–3.5 | Good | Automotive housings, brackets |
| A380 | Good | 320–340 | 1.0–2.5 | Moderate | Electronics, frames |
| EN AC-46000 | Good | 200–240 | 1.5–3.0 | Good | Appliance parts, general use |
| B390 | Poor | 380–450 | 1.0 | Difficult | Wear-resistant parts |
| A356 | Moderate | 250–280 (T6: 310–330) | 5–10 (T6) | Good | High-strength components |
Note: Numbers above are typical, not guaranteed. Actual casting conditions, wall thickness, and mold design will impact these values.
How Alloy Choice Affects Cost and Lead Time
Most buyers don’t realize how much alloy selection affects the budget and delivery schedule. Here’s what we’ve seen:
- Tooling Time: Alloys with poor flowability (like B390) require more complex gating and venting, which increases mold development time.
- Post-Processing: Heat-treatable alloys like A356 need T6 treatment after casting, which adds 3–5 days to the timeline.
- Recycling Impact: Recycled ADC12 is cheap and widely used, but needs proper quality screening (we do X-ray and spectrometer checks). Virgin material costs more but provides tighter control.
- MOQ Differences: Some specialized alloys like B390 or A356 require higher melting volumes—usually 300 kg minimum per melt.
If speed and budget are tight, ADC12 or A380 often win. If performance matters most, we help you weigh the trade-offs.
How to Match Alloy to Application Needs
Here’s how we typically advise buyers based on part usage:
- For thin-wall casings: Go with ADC12 or A380. They flow well and fill sharp corners.
- For parts under impact or load: A356 with T6 treatment offers strength and ductility.
- For high wear resistance: B390 or A390, but machine it carefully.
- For corrosion-prone environments: A360 or EN AC-44300 (AlSi12Fe), especially in humid or salt-laden conditions.
Tell us how the part will be used—not just how it should look—and we’ll recommend the best-fit alloy.
hat Alloy We Commonly Recommend (and Why)
From our production data in 2024, about 78% of our exports used ADC12, especially for auto, lighting, and energy housing projects. For U.S. and Canada orders, A380 is often requested due to familiar ASTM standards. For customers needing strong mechanical performance, A356 with T6 is becoming more common, especially for EV or machinery projects.
Here’s a breakdown of alloy usage from our recent projects:
- Automotive: ADC12, A380
- Medical: A356 (for fine-machined parts)
- Energy: EN AC-46000
- Lighting: ADC12
- Machinery: A319 / A356
We’re flexible, but we always push for alloys that balance cost, castability, and the buyer’s performance goals.
A Buyer’s Checklist for Alloy Selection
If you’re preparing an RFQ or starting a new project, here’s what you should define before picking an alloy:
- What is the part’s function?
- Is strength or appearance more important?
- Will the part be post-machined or coated?
- Are there any corrosion risks?
- Do you need certification (RoHS, REACH, etc.)?
- What international standard (JIS/ASTM/EN) do you need to meet?
- What’s your expected volume and frequency?
When buyers provide this info, we can suggest the right alloy quickly—and get mold design started faster.
Need Help Choosing the Right Alloy?
Choosing the right aluminum alloy isn’t about chasing the “best” one on paper—it’s about selecting what fits your part, production timeline, and cost limits. We’ve helped hundreds of buyers make that decision across many industries. If you’re unsure which alloy fits your project, just ask—we’re happy to give a realistic answer without the sales talk.
📩 Reach out to us at yongzhucasting@gmail.com with your drawings and project details.
