Views: 0 Author: Site Editor Publish Time: 2025-09-23 Origin: Site
Zamak is one of the most widely used and important die-casting alloys in manufacturing today, especially suitable for hot chamber die-casting processes. The main difference between them lies in the different contents of copper (Cu) and magnesium (Mg), which directly affects their mechanical properties, dimensional stability and processing performance. The mechanical property are as follows:
Features | Zamak3 | Zamak5 | Zamak2 | Zamak7 |
Tensile Strength | 283 MPa | 328 MPa | 359 MPa | 269 MPa |
Hardness Brinell | 82 | 91 | 105 | 80 |
Impact Strength | 48 J/m | 58 J/m | 65 J/m | 48 J/m |
Cost | lowest | average | high | average |
Detailed analysis and comparison:
1. Zamak 3 (The most universal and commonly used)
•Feature:It is the most widely used among all zinc alloys and is the industry standard. It contains no copper and has excellent fluidity and casting performance,making it easy to fill complex molds and thin-walled areas.
•Advantages:The best casting performance, good surface finish,easy to electroplate and spray,and the lowest cost.
•Disadvantage:Among the four alloys,its mechanical strength, hardness and creep resistance are relatively the lowest (but still far higher than many other die-casting materials).
•Application:In the vast majority of situations where extremely high strength and wear resistance are not required,such as toy models,zippers,accessories,home hardware,electronic casings,etc.
2. Zamak 5 (High strength)
•Features:Approximately 1% copper is added on the basis of Zamak3. The addition of copper significantly enhanced tensile strength, hardness and impact toughness.
•Advantages:It has better mechanical properties than Zamak3 while maintaining good casting performance.
•Disadvantages:The copper content makes it more prone to micro-corrosion (ageing/dimensional changes) than Zamak3,and its long-term dimensional stability is slightly inferior to that of Zamak3 and 7. The cost is slightly higher than that of Zamak3.
•Application:Higher strength structural and functional components are required,such as automotive parts,agricultural machinery parts,hand-held tools,high-load hinges and handles,etc.
3. Zamak 2 (High hardness and high wear resistance)
•Features:It has the highest copper content (about 3%),which gives it the highest tensile strength, hardness and wear resistance among the four alloys.
•Advantages:Excellent mechanical properties and creep resistance,highly wear-resistant,and long service life.
•Disadvantages: It has the poorest casting performance (relatively low fluidity),and the most prominent dimensional stability issue (the most obvious shrinkage due to long-term natural aging hardening caused by high copper content). The cost is also the highest.
•Application:Parts with extremely high requirements for wear resistance and strength,such as sliding bearings,core components of locks,high-specification hardware parts,wear-resistant bushings,etc. Its current application has gradually decreased and has been replaced by other materials or Zamak 5.
4. Zamak 7 (High purity and high stability)
•Features:Its composition is almost the same as that of Zamak 3 (low copper),but the key difference lies in that it uses raw materials of higher purity (over 99.99% superior zinc),and the magnesium content is controlled more precisely and at a lower level.
•Advantages:
Optimal long-term dimensional stability: Due to the extremely low content of impurities (especially lead, tin, and cadmium), there is almost no dimensional expansion or strength attenuation caused by intergranular corrosion,making it highly suitable for precision parts.
Excellent fluidity: Even superior to Zamak 3,it is highly suitable for die-casting thin-walled and structurally complex parts.
•Disadvantage:The mechanical strength is slightly lower than that of Zamak3 and 5. The cost is relatively high due to the use of high-purity zinc.
•Application:High-precision,thin-walled complex parts, parts that require long-term dimensional stability,such as instrument parts, precision gears,high-specification locks,camera parts,etc.·
How to choose？
• For the lowest cost and general use: Zamak 3 is the first choice.
• Higher strength and toughness required: Choose Zamak 5.
• Extremely high hardness and wear resistance are required, and poor castability can be accepted: consider Zamak 2 (but carefully evaluate before use).
• For thin-walled, complex structures, or those requiring extremely high long-term dimensional stability and accuracy: Choose Zamak 7.
In practical applications, Zamak 3 and Zamak 5 occupy the vast majority of the market. The application scope of Zamak 2 has been narrowed due to its obvious shortcomings. Zamak 7 plays an irreplaceable role in specific high-end and precision fields.
