Zamak 7: The Ultimate FAQ Guide

Let’s look at some of the fundamental aspects you need to know about Zamak 7 alloy.

What Is The Composition Of Zamak 7?

Zamak 7

Zamak 7

Zamak 7 also known as Zinc alloy 7 is a combination of aluminum, magnesium and copper with zinc acting as base material.

It derives its name from its material’s set composition range; Zinc (Z), Aluminum (A), Magnesium (MA), Kupfer (Copper).

Zamak 7 alloy contains less quantities of magnesium with better ductility than Zamak 3 thus is considered a high-purity alloy. The added alloys impurities are controlled by adding small quantities of nickel which also reduces inter-granular corrosion.

The elements which make up Zamak 7 material include the following and in a given quantity as follows:

ElementQuantity in percentage (%)Element Properties
Aluminum (Al)3.5-4.3
Copper (Cu)0.25
Iron (Fe)0.075 max
Nickel (Ni)0.005-0.02Controls impurities
Magnesium (Mg)0.005-0.02Low Mg Increases fluidity
Lead (Pb)0.003 max
Cadmium(Cd)0.002 max
Tin (Sn)0.002 max
Zinc (Zn)Balance

What Are The Properties For Zamak 7?

Zamak 7 possesses physical, chemical and mechanical properties due to its element composition.

Physical properties of Zamak 7 are as follows measured in metric and imperial values;

Physical propertyMetric valueImperial value
Melting range381—387 °C718—729 °F
Coefficient of thermal expansion27.4 μm/m-°C15.2 μin/in-°F
Thermal conductivity113 W/m-K784 BTU-in/hr-ft2-°F
Electrical resistivity6.4 μΩ-cm2.5 μΩ-in
Specific heat capacity419 J/kg-°C0.100 BTU/lb-°F
Casting temperature395—425 °C743—797 °F

The chemical properties of Zamak 7 include the individual elements which make up zinc alloy 7 unique. Each element possesses a unique property that affects the final property of Zamak 7.

Mechanical properties of Zamak 7 contribute to its application in different areas such as in manufacturing of appliances, die cast toys, etc.

Some of those properties include:

Mechanical propertyMetric valueImperial value
Brinell hardness8080
Shear strength 214MPa31,000 psi
Elongation at fracture13-14%
Comprehensive yield strength 221MPa32Psi
Impact strength 58.0 J42.8ft-lbf
Fatigue strength (reverse bending 5×108 cycles) 47.0 MPa 6,820psi
Yield strength285 MPa41,300 psi
Ultimate Tensile strength 285MPa41,300 psi

Where Is Zamak 7 Material Applied?

Zamak 7 is highly ductile, fluid and with improved surface finish as a result of the strictly controlled alloy impurities.

It is therefore applied in different areas such as:

  • Die casting for making thin walled components necessary for good surface finish.
  • Manufacture of some firearms
  • Used for damping and vibration attenuation
  • Making of appliances such as door locks, handle, key chains, etc.

How Does Zamak 7 Compare To Zamak 3?

Zamak 7 and Zamak 3 are both zinc alloys composed of different alloy components with zinc as the base metal.

Zamak 7 however has low content of magnesium (0.02) element thus making it more fluid compared to Zamak 3 (0.05).

Both Zamak 7 and Zamak 3 have aluminum content of 4% with the other elements contents varying.

Zamak 3 is the standard zinc alloy due to its balanced element composition, physical and mechanical properties. As a result, Zamak 3 is widely used in die casting due to stability and longevity compared to Zamak 7.

What Are The Benefits Of The Zamak 7?

Zamak 7 boost of several advantages due to its mechanical and physical properties such as rigidity, strength and toughness. All this combined property contributes to better performance and economical castability.

  • Strength and ductility

Zamak 7 is highly strong and with superior elongation properties thus making it formidable for use in designs and bending operations.

  • Rigidity

Zinc alloys are rigid and equally elastic in characteristic just like other materials. However, their level of rigidity is far superior than other die cast.

  • Toughness

Zamak 7 is highly resistance to impact and strong compared to other materials like plastics, aluminum alloys and grey cast iron.

  • Anti-sparking

Zinc alloy is non-sparking making Zamak 7 ideal for use in hazardous areas such as coal miners, refineries, etc.

  • Easy finishing

Zamak 7 casting material can be easily polished, chromate or anodized or plate painted for decorative purposes.

  • Long shelf-life

Zamak 7 has low casting temperature making it experience less thermal shock when working with it. This extends the casting life of zinc alloys compared to aluminum alloy.

  • Thin wall castability

Thin wall castings can be made on zinc due to high-casting fluidity of Zamak 7.

  • Machinability

Due to trouble free mechanization of zinc material without wear and tear during use, makes it a great tool.

  • Recyclable

Zinc alloy are known to have clean melting points which is toxic free making it a recyclable and reusable material.

How Can You Check Quality Of Zamak 7?

One of the ways to confirm the quality of Zamak 7 is by checking its elements quantities.

Excessive presence of impurities will interfere with the corrosive property hence making it loose this characteristic.

Zamak 7

Zamak 7

Is Zamak 7 Suitable For Die Casting?

Yes, it is.

This is because Zamak 7 is has high fluidity thus allowing thin wall casting regardless of the process.

What Are Limitations Of Zamak 7?

  • Zamak 7 is heavy in weight hence it is not applicable in lightweight operations.
  • Very high temperature can easily damage zinc casting tensile strength making it fragile.
  • The impact strength of Zamak 7 decreases significantly with a drop in temperature.
  • Other elements in excess quantities such as lead and tin decreases its corrosive property.

How Strong Is Zamak 7?

Zamak 7 has an ultimate tensile strength of 41,300 psi which makes using it during bending, elongation operations possible.

Besides, they have an impact resistance of 58.0 J making them tougher than other alloys such as aluminum alloys.

How Does Zamak 7 Compare To Aluminum Alloys?

  • Zamak 7 is made from zinc alloys classification and other elements in different quantities with zinc as base material. Aluminum alloys is derived from aluminum alloy classifications and other elements.
  • Zamak 7 die casting is easier to achieve without additional machining compared to aluminum alloy casting.
  • Zamak 7 has excellent corrosion resistance compared to aluminum alloy.
  • Zamak 7 has better mechanical properties than aluminum alloy.
  • Zamak 7 has better fluidity than aluminum alloy thus can be used to make thinner parts of die casting.
  • Zamak 7 is a heavy weight material and durable whereas aluminum alloy is light weighted structural material.

For any questions or inquiry about zinc die casting, contact u snow.

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