Zamak 7 Zinc Alloy Material Guide

Overview

Zamak 7 is a high-purity zinc die-casting alloy developed from Zamak 3, offering improved fluidity, ductility, surface finish quality, corrosion resistance, and dimensional accuracy. With tighter impurity controls and reduced magnesium content, Zamak 7 is specifically designed for precision die casting applications requiring thin walls, complex geometries, and premium surface appearance.

Compared with Zamak 3, Zamak 7 provides better casting performance and improved plating characteristics while maintaining similar mechanical properties.

Zamak 7 is widely used in:

  • Precision Die Cast Components
  • Decorative Hardware
  • Consumer Electronics
  • Automotive Trim Parts
  • Cosmetic Packaging
  • Electrical Components
  • Furniture Hardware
  • High-End Consumer Products

Because of its excellent castability and superior surface finish, Zamak 7 is often selected for decorative and cosmetic applications where appearance is critical.


Material Specification

PropertyValue
Material DesignationZamak 7
UNS NumberZ33522
ASTM StandardASTM B86
Material FamilyHigh-Purity Zinc-Aluminum Alloy
Density6.6 g/cm³
Magnetic PropertyNon-Magnetic
Typical Manufacturing ProcessHigh Pressure Die Casting
Standard FormsDie Cast Components, Ingots

Chemical Composition

ElementContent (%)
Zinc (Zn)Balance
Aluminum (Al)3.8–4.3
Magnesium (Mg)0.005–0.02
Copper (Cu)≤0.03
Iron (Fe)≤0.02
Lead (Pb)≤0.003
Cadmium (Cd)≤0.003
Tin (Sn)≤0.001

The lower magnesium and impurity levels improve casting fluidity and surface quality.


Mechanical Properties

As-Cast Condition

PropertyValue
Tensile Strength260–290 MPa
Yield Strength200–230 MPa
Elongation12–20%
Hardness80–95 HB
Elastic Modulus83 GPa

Typical Mechanical Performance

PropertyValue
Fatigue ResistanceGood
Impact StrengthGood
DuctilityExcellent
Dimensional StabilityExcellent

Mechanical properties are similar to Zamak 3, with slightly improved ductility.


Physical Properties

PropertyValue
Density6.6 g/cm³
Melting Range380–390°C
Thermal Conductivity113 W/m·K
Electrical Conductivity28% IACS
Electrical Resistivity0.062 μΩ·m
Thermal Expansion Coefficient27 × 10⁻⁶/K
Specific Heat Capacity420 J/kg·K

Strength-to-Weight Ratio

MaterialDensity (g/cm³)Tensile Strength
Zamak 76.6280 MPa
Zamak 36.6283 MPa
Zamak 56.6330 MPa
Aluminum A3802.73325 MPa

Zamak 7 prioritizes castability and appearance over maximum strength.


Corrosion Resistance

EnvironmentPerformance
Indoor EnvironmentExcellent
Dry AtmosphereExcellent
Humid EnvironmentGood
Industrial AtmosphereGood
Outdoor ExposureModerate
Salt Spray EnvironmentFair

The high-purity composition provides slightly improved corrosion resistance compared with standard Zamak grades.

Recommended surface treatments:

  • Chrome Plating
  • Nickel Plating
  • Copper-Nickel-Chrome Plating
  • Powder Coating
  • Painting
  • Passivation

Surface Finish Quality

PropertyRating
Surface SmoothnessOutstanding
Decorative AppearanceOutstanding
Plating AdhesionExcellent
Cosmetic QualityExcellent

Zamak 7 is often preferred for decorative applications due to its superior surface characteristics.


Castability

PropertyRating
Die Fill CapabilityOutstanding
Thin Wall CastingOutstanding
Complex Geometry CastingOutstanding
Dimensional AccuracyExcellent

Zamak 7 exhibits better fluidity than Zamak 3, making it ideal for highly detailed castings.


Machinability

ProcessRating
CNC TurningExcellent
CNC MillingExcellent
DrillingExcellent
TappingExcellent
GrindingGood

Machinability Comparison

MaterialMachinability
Brass C360Excellent
Zamak 7Excellent
Zamak 3Excellent
Aluminum 6061Excellent

Secondary machining requirements are often minimal.


Heat Treatment

Heat Treatment Characteristics

PropertyPerformance
Heat Treat HardeningNot Recommended
Structural StabilityExcellent
Aging ResistanceExcellent
Dimensional StabilityExcellent

Like other Zamak alloys, Zamak 7 is not normally heat treated.


International Equivalent Grades

StandardEquivalent Grade
ASTM (USA)Zamak 7
UNSZ33522
DIN (Germany)ZnAl4 Special Purity
EN (Europe)ZL0400HP
ISOZamak 7
JIS (Japan)High Purity Zinc Alloy
GB/T (China)High Purity Zinc Die Casting Alloy

Available Forms

Product TypeAvailability
Die Cast ComponentsYes
Precision Cast PartsYes
Decorative CastingsYes
IngotsYes

Typical Applications

Consumer Electronics

  • Mobile Device Housings
  • Camera Components
  • Wearable Device Parts
  • Electronic Enclosures

Decorative Hardware

  • Door Handles
  • Cabinet Hardware
  • Furniture Fittings
  • Architectural Hardware

Automotive Industry

  • Interior Trim Components
  • Decorative Components
  • Emblems
  • Control Knobs

Cosmetic Industry

  • Perfume Caps
  • Cosmetic Packaging
  • Luxury Product Components

Electrical Industry

  • Connector Housings
  • Precision Electrical Components
  • Decorative Electrical Hardware

Consumer Products

  • Premium Household Products
  • Decorative Accessories
  • Precision Hardware

Manufacturing Characteristics

Manufacturing ProcessRating
High Pressure Die CastingOutstanding
CNC MachiningExcellent
ElectroplatingOutstanding
PolishingOutstanding
Surface FinishingOutstanding

Advantages

Superior Castability

Excellent flow characteristics for thin-wall and complex castings.

Outstanding Surface Finish

Ideal for decorative and cosmetic applications.

Excellent Plating Performance

Provides exceptional adhesion for chrome and nickel plating.

High Dimensional Accuracy

Suitable for precision die-cast components.

Good Corrosion Resistance

Performs well in indoor and commercial environments.

Excellent Ductility

Improved elongation compared with many zinc alloys.


Limitations

Lower Strength Than Zamak 5 and Zamak 2

Not intended for high-load structural applications.

Higher Density Than Aluminum

Less suitable for lightweight products.

Moderate Outdoor Durability

Protective coatings recommended for exterior applications.

Limited High-Temperature Performance

Not recommended for continuous use above 100°C.


Comparison with Other Zamak Alloys

PropertyZamak 7Zamak 3Zamak 5Zamak 2
CastabilityBestOutstandingExcellentExcellent
Surface FinishBestExcellentExcellentGood
StrengthModerateModerateHigherHighest
DuctilityHighestHighModerateLower
Plating QualityBestExcellentVery GoodGood

Comparison with Common Die Casting Materials

MaterialDensityTensile StrengthSurface Quality
Zamak 76.6 g/cm³280 MPaOutstanding
Zamak 36.6 g/cm³283 MPaExcellent
Zamak 56.6 g/cm³330 MPaExcellent
Aluminum A3802.73 g/cm³325 MPaGood

Available Surface Finishes

Raw Finishes

  • As-Cast Finish
  • Fine Cast Finish

Functional Finishes

  • Precision Machined Finish
  • Polished Finish
  • Satin Finish

Decorative Finishes

  • Chrome Plating
  • Nickel Plating
  • Black Nickel Finish
  • Powder Coating
  • Painted Finish

Frequently Asked Questions (FAQ)

What is Zamak 7?

Zamak 7 is a high-purity zinc die-casting alloy designed for superior castability, surface finish quality, and plating performance.

What is Zamak 7 used for?

Typical applications include:

  • Decorative Hardware
  • Electronics Components
  • Cosmetic Packaging
  • Automotive Trim
  • Precision Die Cast Parts

What is the equivalent material to Zamak 7?

Common equivalents include:

  • UNS Z33522
  • High Purity ZnAl4 Alloy
  • ZL0400HP

What is the difference between Zamak 7 and Zamak 3?

PropertyZamak 7Zamak 3
Surface FinishBetterExcellent
CastabilityBetterExcellent
DuctilitySlightly HigherHigh
StrengthSimilarSimilar

Is Zamak 7 corrosion resistant?

Yes. It provides good corrosion resistance and performs exceptionally well when plated or coated.

Can Zamak 7 be machined?

Yes. Zamak 7 offers excellent machinability and often requires minimal secondary operations.

Why choose Zamak 7?

Because it combines:

  • Superior Castability
  • Outstanding Surface Finish
  • Excellent Plating Quality
  • High Dimensional Accuracy
  • Decorative Appearance

Is Zamak 7 suitable for decorative products?

Yes. Zamak 7 is specifically designed for premium decorative and cosmetic applications.

Does GCNOV provide custom manufacturing services for Zamak 7?

Yes. GCNOV provides:

  • Zinc Die Casting
  • Precision CNC Machining
  • Chrome Plating
  • Surface Finishing
  • Prototype Development
  • Low-Volume Production
  • Mass Production
  • Decorative Metal Components