+86-13928348837
Zinc Alloy CNC Machining Services from Trusted China Suppliers and Factory for Automotive and Electronics
Zinc alloys typically refer to alloys with zinc as the base, primarily alloyed with elements such as aluminum, copper, and magnesium. Their most prominent feature is excellent castability, making them suitable for manufacturing parts with complex shapes.
Simultaneously, their superior machinability allows subsequent CNC precision machining to easily achieve high dimensional accuracy and excellent surface finish.
Furthermore, zinc alloys offer good wear resistance, damping capacity, and comprehensive electromagnetic shielding (EMI/RFI) capability, making them an engineering material that combines functionality with economy.
★
Common Zinc Alloy Grades and Characteristics
Grade 01
Zamak 3 (Zinc Alloy No. 3)
⚙️ Characteristics
The most versatile and commonly used die-casting zinc alloy. It possesses the best fluidity and dimensional stability, along with good mechanical properties and surface treatment performance. Its low copper content means its creep resistance and strength are slightly lower than Zamak 5, but it offers better ductility.
🏭 Typical Applications
Complex thin-walled parts without extremely high strength requirements, such as toy models, zipper pulls, small gears, decorative items, and numerous consumer electronics housings.
Zamak 3 Typical Properties (As Die-Cast)
| Property | Value | Notes |
| Tensile Strength (MPa) | 280 – 320 | Good overall strength |
| Yield Strength (MPa) | — | |
| Elongation at Break (%) | 10–20 | Exhibits good ductility |
| Hardness (Brinell) | ~ 82 | |
| Density (g/cm³) | 6.6 | Significantly higher than aluminum and plastics |
| Note: Values are typical ranges, specific to casting process and condition. | ||
Grade 02
Zamak 5 (Zinc Alloy No. 5)
⚙️ Characteristics
Based on Zamak 3 with the addition of about 1% copper, thereby increasing tensile strength, hardness, and creep resistance, but slightly reducing impact toughness and ductility. It is the most widely used high-strength die-casting zinc alloy.
🏭 Typical Applications
Functional and structural parts requiring higher strength and wear resistance, such as automotive door locks, fuel system components, tool housings, premium hardware, and business machine parts.
Zamak 5 Typical Properties (As Die-Cast)
| Property | Value | Notes |
| Tensile Strength (MPa) | 330 – 380 | Strength higher than Zamak 3 |
| Yield Strength (MPa) | — | |
| Elongation at Break (%) | 7–15 | |
| Hardness (Brinell) | ~ 91 | Higher hardness, more wear-resistant |
| Density (g/cm³) | 6.7 | Similar to Zamak 3 |
| Note: Values are typical ranges, specific to casting process and condition. | ||
Grade 03
ZA-8 (Zinc-Aluminum Alloy No. 8)
⚙️ Characteristics
A zinc-aluminum alloy containing about 8.4% aluminum, typically produced by gravity casting. It has the best castability among all ZA series alloys and offers excellent bearing properties and wear resistance. Compared to the Zamak series, it retains better strength and dimensional stability at elevated temperatures.
🏭 Typical Applications
Bearings, bushings, sliders, wear-resistant components, and engineering structural parts that need to operate in moderately elevated temperature environments.
Grade 04
Kirksite (Mold Zinc Alloy)
⚙️ Characteristics
A zinc-based alloy specifically designed for manufacturing prototype molds, low-melting-point injection molds, and fixtures. It has a low melting point, is easy to machine, and can quickly and cost-effectively replicate complex mold cavities for small-batch plastic part trial production or sheet metal forming.
🏭 Typical Applications
Prototype injection molds, blow molds, sheet metal stamping/form dies, checking fixtures, and jigs.
Frequently Asked Questions
What is the main difference between Zamak 3 and Zamak 5?
Zamak 5 contains approximately 1% more copper than Zamak 3, which increases its tensile strength, hardness, and creep resistance. However, this comes at the cost of slightly reduced ductility and impact toughness. Zamak 3 is preferred when better ductility and dimensional stability are required, while Zamak 5 suits applications demanding higher strength and wear resistance.
Why are zinc alloys considered a good choice for die casting?
Zinc alloys have excellent fluidity and castability, allowing them to fill complex thin-walled mold cavities with high precision. They also have a relatively low melting point, which reduces energy consumption and extends die life. Combined with their good surface finish and dimensional stability, zinc alloys are highly cost-effective for high-volume die casting production.
Can zinc alloy parts be used in high-temperature environments?
Standard Zamak alloys (such as Zamak 3 and Zamak 5) are generally not recommended for continuous use above 100°C, as they may experience creep and dimensional changes. ZA-8, with its higher aluminum content, offers better performance at moderately elevated temperatures and is a more suitable choice for applications requiring thermal stability.
What surface treatments are compatible with zinc alloy parts?
Zinc alloy parts are compatible with a wide range of surface treatments, including electroplating (chrome, nickel, copper), powder coating, painting, anodizing-like processes, and chemical conversion coating. These treatments can enhance corrosion resistance, improve aesthetics, and increase surface hardness depending on the application requirements.
What is Kirksite alloy primarily used for, and what are its advantages?
Kirksite is a zinc-based alloy specifically designed for tooling applications such as prototype molds, injection molds for small-batch production, and forming dies. Its key advantages include a low melting point for easy casting, excellent machinability, and the ability to quickly replicate complex geometries at a lower cost compared to steel tooling — making it ideal for rapid prototyping and short production runs.
How does ZA-8 differ from the Zamak series of zinc alloys?
ZA-8 contains a significantly higher aluminum content (approximately 8.4%) compared to the Zamak series (which typically contains 3.5–4.3% aluminum). This higher aluminum content gives ZA-8 better mechanical properties at elevated temperatures, superior bearing and wear resistance, and improved strength. However, ZA-8 is typically produced by gravity casting rather than pressure die casting, which affects its suitability for certain manufacturing processes.
Finishes and Post-Processing Options
The zinc alloy substrate is highly suitable for various surface treatments to enhance decoration, protection, or functionality:
Electroplating: Such as chrome, nickel, gold, or silver plating, providing a highly decorative appearance, excellent wear and corrosion resistance. This is the most common choice.
-
Passivation or Chromate Conversion Coating:
-
Powder Coating:
-
Painting:
-
Physical Vapor Deposition (PVD):
Design and Machining Considerations
-
Process Selection:
-
Design Considerations:
-
Material Selection:
Zamak 3 and 5 are suitable for the vast majority of general-purpose parts requiring good appearance and strength; ZA-8 is better for wear and bearing applications; for making rapid tooling, choose specialized alloys like Kirksite.
Ready to Start Your CNC Project?
Send us your drawings to receive professional manufacturing solutions.