Singapore OEM teams often default to Aluminium for housings and micro components. On CAD this seems harmless. On the production floor it becomes one of the most common cost leaks we see. Parts under 50 grams that demand ±0.05 mm or tighter should not start with A380 by default. Many Aluminium problems
are actually material choice problems that vanish when the same part is designed for Zinc.
At Ssoss Cast, most small precision components begin with an alloy review before tooling. Zinc alloys Zamak 3 and 5 offer capabilities that Aluminium cannot match for tight tolerances, damping and net-shape geometry.
For a neutral technical reference, engineers can also review NADCA’s Zinc Die Casting Design Guidelines which outline tolerance and flow advantages.
When Should You Choose Zinc Instead of Aluminium?
Choose Zinc for parts under 50 grams requiring tight features. Zamak 3 and 5 regularly hold ±0.01 mm in our production lines, which reduces machining time by 30 to 50 percent compared to A380. Zinc’s damping is 3 to 5 times higher than Aluminium, making it ideal for small enclosures, connectors and mechanisms that need stability.
Why Zinc Offers Superior Dimensional Control and Surface Quality
Zinc is cast at roughly 420°C in a hot chamber system. Aluminium is cast above 650°C. Lower temperature means less thermal shock and less tool wear. The result is cleaner parting lines, better repeatability and sharper fine details.
In our facility, tool steels used for Zinc last far longer than those for Aluminium of similar complexity. This stability directly supports tight tolerances in long-run programs.
For larger housings or components where stiffness-to-weight matters more than micro features, review our Aluminium Die Casting capabilities.
The Most Common DFM Mistake We See
Engineers specify A380 out of habit, then add CNC passes to reach ±0.02 mm on pockets and holes. Zinc could cast these directly.
This adds unnecessary handling time and increases cost by $1.50–$2.50 per part on runs above 50 thousand units.
📊 Technical Specification Infographic
Alt Text: Zinc die casting dimensional accuracy infographic
Text Overlay: Tighter Tolerances. Lower Costs.
Net-Shape Capabilities: The Real Cost Advantage
For small components, cost is driven by finishing, not by metal cost. Zinc’s flow characteristics allow:
- Thin walls down to 0.4 mm in stable production
- Micro features such as threads, latches and snap points formed as-cast
- Reduced porosity through better mold fill
- Stable bosses and ribs even when small
One of our telecom clients shifted from an Aluminium connector shell to Zamak 5. Once redesigned for Zinc flow, the team observed:
- 48 percent reduction in machining time
- Cleaner surfaces requiring less final brushing
- Tool life increased, reducing downtime
For end-to-end support, see our Turnkey Project workflow.
📊 Net-Shape Diagram
Alt Text: Zinc net-shape casting features diagram
Text Overlay: Cast Once. Finish Less.
Alloy Comparison: Zamak 3 vs Zamak 5 vs A380 Aluminium
| Property | Zamak 3 | Zamak 5 | A380 Aluminium |
|---|---|---|---|
| Fluidity | Excellent | Excellent | Good |
| Dimensional accuracy | Very high | Very high | Medium |
| Damping capacity | High | Very high | Low |
| Strength-to-weight | Medium | Medium-high | High |
| Ideal application | Tight tolerance | Mechanical parts | Larger housings |
Key insight: Zamak 5 is the go-to for parts that see vibration, while Zamak 3 is ideal for tight, stable, electronic enclosure components.
A detailed material overview is also available in our About Die Casting page.
📊 Alloy Chart
Text Overlay: Zinc Wins Where Precision Matters.
Tooling, Defects and Cost: The Real-World Impact of Choosing Zinc
Zinc tools see less stress. Less stress means:
- Longer tool life
- Fewer dimensional shifts over time
- Fewer adjustments or tool welds
- Cleaner parting lines
- Lower scrap
Defects avoided by switching from Aluminium to Zinc:
- Porosity from poor fill
- Warpage in thin pads
- Drag marks from difficult ejection
- Machining chatter due to inconsistent surfaces
Zinc gives a safer flow window that reduces firefighting during production.
🔄 DFM Process Flow – Small Precision Parts
Caption: One design review often prevents weeks of chasing defects later.
Case Study: Eliminating Machining Stages for a Singapore Electronics OEM
A small RF housing originally designed in Aluminium required a full secondary CNC pass for holes and slots. Scrap rates were also high due to porosity around thin ribs.
Original issues
- A380 struggled to fill long micro channels
- Warpage caused variation in hole position
- Machining time exceeded predicted cycle
- Tool wear increased after 20 thousand shots
Ssoss Cast redesign
- Switched to Zamak 5
- Added fillets to thin ribs to support flow
- Adjusted gating for smoother fill
- Cast mounting holes directly into geometry
- Removed the entire secondary machining step
Results
- Zero machining required for mounting features
- Scrap dropped by over 70 percent
- Cycle time shortened since handling was reduced
- Tool maintenance intervals nearly doubled
These improvements came from an alloy change and simple geometry updates, not from major redesign.
📈 Case Study Visual
Text Overlay: -70% Scrap | 0 CNC Passes | Same Function
Working With Ssoss Cast as a Zinc Design Partner
Good Zinc part design comes from collaboration between design engineers and toolmakers.
A typical engagement with Ssoss Cast includes:
- Early review of 3D model with recommendations
- Identification of features that Zinc can cast net-shape
- Alloy recommendation (Zamak 3 or 5)
- Gate and parting line suggestion
- Sampling and dimensional report
- Adjustment and final tool lock
For small components, these steps avoid most of the delays that come from misapplied Aluminium.
💬 Quote Card
Quote:
Small parts reward the right alloy. Precision comes from design choices, not luck.
Quick Recap
- Zinc excels at tight tolerances and net-shape features.
- Aluminium is strong, but not always cost effective for small components.
- Zinc reduces machining time and tool wear.
- Many defects disappear when a part is redesigned for Zinc’s flow behaviour.
- Early DFM with Ssoss Cast prevents costly late-stage firefighting.