Singapore OEM teams do not lose money on alloy choice. They lose it on parts that look fine in CAD but fight the mold every single shot. Warpage, porosity and rework hours all start at the design stage. Many casting problems
are actually design problems that could have been fixed before cutting steel.
At Ssoss Cast, most new projects start with a design review, not a quote. This article distills the kind of guidance their engineers give to OEM teams that want parts that fill, release and machine cleanly without a constant firefight on the shop floor.
For readers who want a neutral process overview, you can also check this short explanation of the die casting process.
Essential Design Practices
A manufacturable aluminium die cast part keeps walls in the 2 to 3 millimetre range for most ADC12 and A380 applications, uses generous fillets of 0.5 to 1.5 millimetres, and includes 1 to 2 degrees of draft on external faces. Combine this with clear gating areas and you usually cut scrap rate and tooling changes by double digit percentages.
🎯 Featured Hero Image
A manufacturable aluminium die cast part is designed with real-world constraints in mind – not just CAD perfection. The split view shows the critical difference between theoretical design and practical manufacturing requirements including draft angles, wall thickness measurements, and mold considerations.
Featured Image – Engineer at Work
Image concept: Clean editorial style photograph. An engineer at a workstation in a Singapore factory reviews a 3D model of an aluminium housing. On screen, coloured overlays highlight different wall thickness zones and draft directions. Subtle Ssoss Cast branding on a notebook or mug.
Wall Thickness, Fillet Radii And Draft Angles
Thin walls save weight and material. Push them too far and you get misruns and weak sections. Thick walls feel safe
in CAD. Inside a hot chamber they invite shrinkage, porosity and long cooling times.
Practical wall thickness guide
| Part type | Typical wall range (ADC12 / A380) |
|---|---|
| Small brackets, covers | 1.8 to 2.5 mm |
| Medium housings, motor end covers | 2.0 to 3.0 mm |
| Large structural frames | 2.5 to 4.0 mm |
Use these as a starting point, not a hard rule.
For ribs and bosses, aim for about 60 to 70 percent of the adjacent wall thickness to avoid sinks and hot spots.
Fillet radii
Sharp internal corners create stress and block metal flow.
- Target 0.5 to 1.0 millimetres for small features.
- Go to 1.5 millimetres or more on load paths and junctions of several walls.
- Avoid zero radius corners anywhere metal should flow.
Draft angles
Draft decides whether the casting releases smoothly or fights the ejector pins.
- External faces. At least 1 degree. More if the surface is textured.
- Internal walls and cores. 1.5 to 2 degrees is safer.
- Deep ribs and pockets. Increase draft as depth increases to avoid drag marks.
In design reviews, it is common to see zero draft on internal pockets. They look impressive in a design review slide. They become a constant sticking point once the mold goes into production.
📊 Technical Specifications Infographic
This comprehensive technical diagram shows the three critical dimensions that every die casting designer must control: wall thickness zones (2.0-3.0mm for most applications), fillet radius specifications (0.5-1.5mm for optimal flow), and draft angles (1-2° for smooth ejection). The reference table provides quick lookup values for different part sizes.
Simple Wall Thickness Diagram
Image concept: Flat illustration that shows a simple U shaped cross section. Labels point to wall thickness, rib thickness ratio and draft angle arrows. Include a small mini table of ranges at the side.
2 to 3 mm Walls. 1 to 2° Draft. Fewer Headaches.
Alloy Choice Impacts
Alloy choice is not just a material spec line. It influences fluidity, defect risk, machining strategy and corrosion performance.
Here is a simplified comparison of common die casting aluminium alloys used in electronics, machinery and automotive components.
| Alloy | Typical use case | Fluidity / castability | Relative strength | Corrosion behaviour | Machinability |
|---|---|---|---|---|---|
| ADC12 | General purpose housings, brackets, covers | Very good | Good | Good with finishing | Good |
| A380 | Structural and automotive style parts | Good | Very good | Needs coating in harsh air | Fair |
| A413 | Thin wall, leak tight parts, pump bodies | Excellent | Good | Good with proper finishing | Good |
If you want a deeper material breakdown, Ssoss Cast has a practical guide to ADC12 and zinc alloys that covers ranges for silicon, copper and the mechanical properties designers care about.
What this means for design
- Thin walls and complex flow paths A413 and ADC12 handle thinner sections and longer flow distances better than A380. If your part pushes the lower wall limits and has many ribs, lean to an alloy with higher fluidity.
- Strength and crash loads For parts that will be stressed, such as brackets that see shock loads, A380 strength can justify slightly thicker walls to keep stiffness.
- Machining and finishing If you plan significant machining, choose alloys that chip cleanly and hold dimensional stability. For parts that must resist coastal or chemical environments, budget for proper finishing. Decide that while designing bosses and mounting features, not after the first corroded batch.
During DFM discussions at Ssoss Cast, alloy suggestions often change once the team sees real geometry and volumes. A Singapore OEM might specify A380 for strength, but the part is a thin walled IoT enclosure. In practice, ADC12 with a small wall increase can hit strength targets and cast more consistently in small batches.
📊 Alloy Comparison Chart – Detailed
This detailed comparison chart helps engineers make informed alloy selection decisions by visualizing the performance characteristics of ADC12, A380, and A413 across four critical attributes: fluidity/castability for thin walls, strength for structural applications, corrosion resistance for harsh environments, and machinability for post-processing requirements.
Key Insight: ADC12 wins for thin walls • A380 for strength • A413 for leak-tight designs
Simple Alloy Comparison
Image concept: Simple bar chart or radar chart that compares three alloys across four attributes. Clean colours and clear labels that an engineer can read in one glance.
Choose Alloy For Flow, Not Only For Strength
Tooling, Defects And Cost
A part that ignores tooling reality keeps charging
you every time the mold closes. Good design reduces machining, avoids risky cores and keeps cycle time stable.
How design drives tooling cost
- Deep, isolated pockets often require complex side cores or lifters.
- Very thin isolated walls demand precise steel and tighter maintenance.
- Tiny cosmetic details on unseen surfaces reduce tool life for zero value.
When Ssoss Cast reviews new parts, the team flags features that will trigger extra sliders or non standard mechanisms. Removing one sliding core can drop tooling cost by a noticeable percentage and also reduce the chance of downtime in production.
Common defects linked to design
- Porosity Thick junctions that act as hot spots, poor venting due to sudden section changes, or gating into thin sections first.
- Shrinkage sinks Bosses that are the same thickness as the wall, large flat pads with no coring, or logos and recesses in thick areas.
- Surface issues Long unsupported sections that warp, sharp edges that cause micro cracking on ejection.
Often, defect rates fall after simple design tweaks. For example, coring out a thick pad and tying it back with ribs improves cooling and reduces shrinkage. It also saves material.
🔄 DFM Process Flow – Detailed
This process flow visualization demonstrates the iterative Design for Manufacturing (DFM) loop that reduces costly tooling iterations by 15-30%. The five-stage workflow shows how early collaboration between design engineers and die casting specialists catches problems during the CAD phase rather than discovering them during expensive production runs.
Average savings: 15-30% reduction in tooling iterations
Simple Process Flow
Image concept: Horizontal process flow with five boxes. Initial CAD
, DFM with Ssoss Cast
, Tooling and sampling
, Defect feedback
, Refined design and stable production
. Under one box, show a small example of porosity before and after design change.
DFM Loop: Fix It On Screen, Not In Scrap Bins
Case Study: Fixing Leakage And Machining Time For A Singapore OEM
A Singapore based electronics OEM approached Ssoss Cast with an aluminium die cast cover for a fluid handling device. The original design looked compact and robust. In production, it developed two major issues.
- Frequent leakage during pressure testing.
- Long machining times on sealing faces and mounting holes.
Original situation
Key design choices in the first version:
- Thick central pad under the sealing surface.
- Multiple bosses the same thickness as the main walls.
- Zero draft on a deep internal pocket that housed an O ring.
- A380 alloy in a part with long, thin flow paths.
On the line, the casting team fought intermittent porosity under the sealing surface. Machining required extra passes to clean up. Scrap rates climbed on a relatively low volume, high value part.
Redesign moves
The Ssoss Cast engineering team sat down with the OEM’s design engineer and proposed a set of changes.
- Changed the alloy to ADC12 for better fluidity given the thin walls.
- Cored out the central pad and replaced it with ribs at about 65 percent of the adjacent wall thickness.
- Added 1.5 degrees of draft to the deep O ring pocket and adjusted the mold split line.
- Introduced larger fillets at the junctions of the sealing boss and main walls.
- Defined a machining datum that reduced repositioning on the CNC.
The DFM session took a few hours, and the CAD update cycle lasted about a week before tooling modification.
Results
After modifying the tool and running a new sampling batch:
- Leak failures during pressure test dropped by roughly 80 percent.
- Average machining time per part fell by 20 to 25 percent due to a cleaner casting and better datum scheme.
- The OEM could hold a tighter flatness range on the sealing face, which gave more confidence as they scaled orders.
Almost all gains came from geometry changes that did not affect the product’s function. The end user never saw the differences. The factory team felt them every day.
✅ Case Study Results – Detailed
This real-world case study from a Singapore electronics OEM demonstrates the dramatic impact of DFM collaboration. The before/after comparison shows how simple design modifications—coring sections, adding draft angles, and optimizing rib ratios—eliminated 80% of leak failures and reduced machining time by 25%, all without changing the part’s function or increasing costs.
Results: -80% Leak Failures | -25% Machining Time | Same Part Cost
Simple Before/After Comparison
Image concept: Split image with Before
on the left and After DFM with Ssoss Cast
on the right. Use coloured overlays to show where material was removed or ribs added. Include small callouts for draft, coring and new datum faces.
Same Function. Cleaner Casting. Lower Cost.
Working With A Die Caster As A Design Partner
Good aluminium die casting design is a team sport. It needs input from design engineers, process engineers and toolmakers.
If you want to sense whether a supplier can genuinely support that, look at their core services and experience base. Ssoss Cast lists both precision aluminium die casting services and plastic injection, CNC machining and finishing, which means they can review the full chain from raw casting to final part.
A typical support flow for new OEM projects looks like this:
- Early review of 3D models and basic functional requirements.
- Identification of risky features for filling, release and machining.
- Suggestions on wall thickness, fillets, draft and alloy choice, usually marked directly inside the 3D file or drawing.
- Agreement on acceptable changes and critical surfaces that must stay untouched.
- Tooling design, sampling and clear feedback on defects and process windows.
- Iteration where needed, before locking the tool for long term production.
This approach suits Singapore based OEMs that run both prototypes and ongoing production. Real cost is not only price per piece. It is the mix of tooling changes, rework hours, scrap and customer complaints.
💬 Shareable Quote Card
Good die cast design is invisible in the final product. You notice it when scrap and tooling issues disappear.
This shareable insight captures the essence of effective DFM—the best designs solve problems before they reach the production floor.
Quick recap
- Keep walls in realistic ranges for the chosen alloy, and keep them as uniform as possible.
- Use fillets and draft generously to help metal flow and release.
- Pick alloys with an eye on fluidity, machining and environment, not only strength.
- Review features that drive complex tooling and high scrap, and remove
nice to have
details that cost more than they give. - Involve a die casting specialist like Ssoss Cast early, while changes are still measured in mouse clicks, not steel.