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Zinc Alloy Zamak 3 vs Zn99.5

Zinc Alloy · grade comparison

Zinc Alloy Zamak 3 and Zn99.5 are both zinc alloy grades. Zamak 3 is the stronger of the two: yield strength 221 MPa (32.1 ksi) against 95 MPa (13.8 ksi) for Zn99.5, about 133% more; tensile strength follows at 283 MPa (41 ksi) vs 140 MPa (20.3 ksi). In exchange, Zn99.5 is the more ductile: elongation 40% versus 10% for Zamak 3, and Zamak 3 is harder (82 HB vs 38 HB). Zamak 3 is lighter (6.6 g/cm³ vs 7.14 g/cm³ for Zn99.5). On the shop floor, Zamak 3 machines more easily (excellent vs very good), Zn99.5 welds better (fair vs poor), and Zamak 3 sits in a lower cost tier (budget, $) than Zn99.5 (premium, $$$).

Zamak 3Choose it when strength drives the design, or when weight is the constraint.

Zn99.5Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

Zamak 3 vs Zn99.5: properties

Zamak 3Zn99.5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

96 GPa13.9 Msi
95 GPa13.8 Msi

Poisson's Ratio

0.27
0.25

Tensile Strength (Ultimate)

283 MPa41 ksi
140 MPa20.3 ksi

Yield Strength (0.2% offset)

221 MPa32.1 ksi
95 MPa13.8 ksi

Elongation at Break

10%
40%

Compressive Strength

414 MPa60 ksi
—

Shear Strength

214 MPa31 ksi
110 MPa16 ksi

Fatigue Strength (Endurance Limit)

48 MPa7 ksi
35 MPa5.1 ksi

Charpy V-Notch Impact (RT)

58 J42.8 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

82 HB
38 HB

Hardness, Vickers

—
40 HV

Same in both: Shear Modulus 38 GPa5.5 Msi · Bulk Modulus 70 GPa10.2 Msi

Physical

Density and transition temperatures.

Density

6.6 g/cm³0.24 lb/in³
7.14 g/cm³0.26 lb/in³

Melting Point (Solidus)

381°C718 °F
420°C787 °F

Liquidus Temperature

387°C729 °F
420°C787 °F

Thermal

How each material carries heat and how hot it can run.

Specific Heat Capacity

419 J/kg·K0.1 BTU/lb·°F
390 J/kg·K0.09 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

27.4 µm/m·K15.2 µin/in·°F
30 µm/m·K16.7 µin/in·°F

Latent Heat of Fusion

110 J/g47.3 BTU/lb
112 J/g48.2 BTU/lb

Min Service Temperature

-20°C-4 °F
-30°C-22 °F

Same in both: Thermal Conductivity 113 W/m·K65.3 BTU/hr·ft·°F · Max Service Temperature (continuous) 100°C212 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
28 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
5.9×10⁻⁸ Ω·m2.32 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-1 V
-1.03 V

Corrosion Resistance

40 / 100
55 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

90 / 100
75 / 100

Machinability Rating (AISI 1212 = 100 %)

120%
70%

Weldability

20 / 100
40 / 100

Formability (cold)

20 / 100
88 / 100

Castability

97 / 100
85 / 100

Brazeability / Solderability

65 / 100
92 / 100

Polishability

85 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

150 L/kg18 gal/lb
120 L/kg14.4 gal/lb

Typical Recycled Content

25%
30%

Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

43 kN·m/kg
20 kN·m/kg

Specific Stiffness (E / density)

14.5 MN·m/kg
13.3 MN·m/kg

Modulus of Resilience

254 kJ/m³
48 kJ/m³

Thermal Diffusivity

40.9 mm²/s
40.6 mm²/s

Thermal Shock Resistance Index

12
6

Strength versus weight

Yield strength against density for every zinc alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

205010020055.566.57Density (g/cm³)Yield strength (MPa) — log scaleZamak 3Zn99.5

Manufacturing and finishing

CapabilityZamak 3Zn99.5
CNC machiningYes—
Casting & forgingYes—
Default conditionAs Cast—
Relative cost$ Budget$$$ Premium
Min. machined wall——
Best machined surface——
Chrome PlatingYes—
E-CoatingYes—
Nickel PlatingYes—
PaintingYes—
Powder CoatingYes—

They share 1 finish: Copper Plating.

Zamak 3 vs Zn99.5 — frequently asked

Is Zamak 3 stronger than Zn99.5?

Yes. Zamak 3 has a typical yield strength of 221 MPa (32.1 ksi) against 95 MPa (13.8 ksi) for Zn99.5 — about 133% more. Tensile strength is 283 MPa (41 ksi) vs 140 MPa (20.3 ksi).

Which is cheaper, Zamak 3 or Zn99.5?

Zamak 3 is the lower-cost material: it sits in the budget tier ($) while Zn99.5 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, Zamak 3 or Zn99.5?

Zamak 3. Its machinability rates excellent (90/100) against very good (75/100) for Zn99.5; for welding the order is Zn99.5 first (fair, 40/100) then Zamak 3 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Zamak 3 and Zn99.5 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.