Definition of Aluminum Alloy Selection Criteria
Applying these criteria early matters far more than material price, which is the smallest element of a finished part's cost. A decision taken at the drawing stage governs yields, finishing options and warranty exposure for the life of the tool. Taiwan foundries commonly stock ADC-12 and ADC-3, so a specification written around those two alloys tends to quote faster and cast more predictably. JoinCast reviews alloy choice with customers in Changhua before tooling begins.
Why This Matters for Your Business
Where a drawing has simply inherited an alloy from an older product, a review is worth the hour it takes. Many parts carry A380 or ADC-12 by habit rather than analysis, and a part now going into an outdoor product may be specified for an environment it will never see, or worse, for one it cannot survive.
Bring the supplier into the decision before the tool is quoted. A foundry running these alloys daily can tell you which one fills your geometry, and that conversation costs nothing at the specification stage.
Related Terms
ADC-12 castability and mechanical properties ADC-3 corrosion resistance Aluminum ingot quality and sourcing Mold Flow Simulation Die Casting Part Weight RangeFAQ
Which aluminum alloy selection criteria matter most for a part that will be machined after casting?
Among aluminum alloy selection criteria, silicon content dominates machining outcomes. High-silicon alloys such as A413 and B390 contain hard silicon particles that wear cutting tools quickly, and NADCA rates both poorly for machining ease. A383, the ADC-12 equivalent, rates 2 of 5, better than A380 at 3, which is one reason it suits parts carrying a lot of post-cast machining.
Porosity deserves equal attention, since cutting into a subsurface void creates a leak path or a cosmetic reject. Agreeing porosity limits on machined faces avoids that argument later. JoinCast's CNC machining capability sits alongside casting in the same facility, so machined samples can be produced from the first tool trial.
How do aluminum alloy selection criteria change when the part needs an anodized finish?
Aluminum alloy selection criteria shift considerably once anodizing is required, because die casting alloys anodize poorly next to wrought aluminum. Silicon leaves a dark, uneven surface and copper interferes with film formation, so a decorative anodized finish on ADC-12 rarely meets appearance expectations. That surprises buyers moving a part from extrusion to casting.
Where appearance matters, powder coating or painting gives a better and more repeatable result, and hard anodizing can still be specified for wear rather than looks. The options and their limits are set out on our aluminum surface treatment page. Agree color and gloss against physical samples rather than a printed swatch.
Should aluminum alloy selection criteria differ when sourcing in Asia rather than North America?
Aluminum alloy selection criteria stay the same in principle, but alloy availability differs by region and that affects both price and lead time. ADC-12 accounts for most die casting output in Japan, Taiwan and China, so an Asian supplier quotes it faster and casts it more predictably than A380, which remains the North American default. The two are close but not identical in iron and zinc limits.
Name the alloy in your own standard and ask the supplier to confirm the equivalent they will pour. Our article on die casting alloy names across regions maps the designations, and confirming the point at quotation stage avoids an unwelcome substitution later.
