Zinc die casting is renowned for producing highly detailed and dimensionally stable components, thanks to zinc's excellent fluidity and low solidification shrinkage (typically around 0.6%). According to the North American Die Casting Association (NADCA) standards, zinc die castings can routinely achieve very tight tolerances, making them ideal for applications that require precise dimensions without the need for extensive post-machining.
For general reference, the following tolerances can typically be achieved:
Feature Size Range | Typical Tolerance (As-Cast) |
|---|---|
0 – 25 mm | ±0.05 mm |
25 – 50 mm | ±0.08 mm |
50 – 150 mm | ±0.13 mm |
>150 mm | ±0.2 mm |
These tolerances apply to linear dimensions and may vary slightly depending on part geometry, wall thickness, and die condition.
Material Choice: Zinc alloys like Zamak 3 and Zamak 5 have consistent flow characteristics and minimal warping, which helps maintain tight tolerances.
Tooling Precision: Tool steels like H13 and P20 are used to ensure dimensional stability throughout high-volume production runs.
Casting Conditions: Controlled injection pressure, die temperature, and cooling rates significantly impact dimensional repeatability.
Secondary Operations: Finishing methods such as post machining can be used for even tighter tolerances (e.g., ±0.01 mm) when needed for functional requirements.
In addition to linear tolerances, zinc die casting also supports controlled flatness, roundness, and coaxiality. Features such as holes, bosses, and internal slots can be cast to near-net shape with minimal deviation, reducing the need for additional finishing.
To ensure the highest dimensional accuracy, we recommend the following:
Precision Casting Services
Zinc Die Casting: Produces complex, high-tolerance parts with consistent quality.
Tooling and Die Support
Tool and Die Creating: High-precision dies made from wear-resistant tool steels to ensure long-term dimensional control.
Post-Processing and Inspection
Post Machining: Tightens tolerances for critical functional surfaces.
Die Castings Inspection: Dimensional validation using precision metrology tools and CMM.
For customers seeking precision zinc components with repeatable tolerances, our one-stop service solution offers integrated support from design through quality control.