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Zinc Alloy Zamak 5 vs Zamak 7

Zinc Alloy · grade comparison

Zinc Alloy Zamak 5 and Zamak 7 are both zinc alloy grades. Zamak 5 is the stronger of the two: yield strength 268 MPa (38.9 ksi) against 210 MPa (30.5 ksi) for Zamak 7, about 28% more; tensile strength follows at 328 MPa (47.6 ksi) vs 283 MPa (41 ksi). In exchange, Zamak 7 is the more ductile: elongation 13% versus 7% for Zamak 5, and Zamak 5 is harder (91 HB vs 80 HB). On the shop floor, Zamak 5 sits in a lower cost tier (budget, $) than Zamak 7 (standard, $$).

Zamak 5Choose it when strength drives the design, or when cost is the deciding factor.

Zamak 7Choose it when the part is bent, formed or impact-loaded.

Zamak 5 vs Zamak 7: properties

Zamak 5Zamak 7

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

38 GPa5.5 Msi
37 GPa5.4 Msi

Bulk Modulus

70 GPa10.2 Msi
—

Tensile Strength (Ultimate)

328 MPa47.6 ksi
283 MPa41 ksi

Yield Strength (0.2% offset)

268 MPa38.9 ksi
210 MPa30.5 ksi

Elongation at Break

7%
13%

Compressive Strength

600 MPa87 ksi
414 MPa60 ksi

Shear Strength

262 MPa38 ksi
214 MPa31 ksi

Fatigue Strength (Endurance Limit)

57 MPa8.3 ksi
47 MPa6.8 ksi

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
58 J42.8 ft·lbf

Hardness, Brinell

91 HB
80 HB

Hardness, Rockwell B

55 HRB
41 HRB

Hardness, Vickers

96 HV
84 HV

Same in both: Elastic (Young's) Modulus 96 GPa13.9 Msi · Poisson's Ratio 0.27

Physical

Density and transition temperatures.

Melting Point (Solidus)

380°C716 °F
381°C718 °F

Liquidus Temperature

386°C727 °F
387°C729 °F

Same in both: Density 6.6 g/cm³0.24 lb/in³

Thermal

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

Thermal Conductivity

109 W/m·K63 BTU/hr·ft·°F
113 W/m·K65.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

100°C212 °F
95°C203 °F

Same in both: Specific Heat Capacity 419 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 27.4 µm/m·K15.2 µin/in·°F · Latent Heat of Fusion 110 J/g47.3 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

26 % IACS
27 % IACS

Electrical Resistivity

6.54×10⁻⁸ Ω·m2.57 µΩ·in
6.4×10⁻⁸ Ω·m2.52 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-1 V
-1.03 V

Corrosion Resistance

38 / 100
45 / 100

Manufacturability

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

Machinability

85 / 100
80 / 100

Machinability Rating (AISI 1212 = 100 %)

85%
80%

Formability (cold)

20 / 100
35 / 100

Castability

96 / 100
97 / 100

Brazeability / Solderability

40 / 100
75 / 100

Same in both: Weldability 15 / 100 · Polishability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

3.4 kg CO₂/kg
3.5 kg CO₂/kg

Embodied Water

110 L/kg13.2 gal/lb
250 L/kg30 gal/lb

Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

50 kN·m/kg
43 kN·m/kg

Modulus of Resilience

374 kJ/m³
230 kJ/m³

Thermal Diffusivity

39.4 mm²/s
40.9 mm²/s

Thermal Shock Resistance Index

14
12

Same in both: Specific Stiffness (E / density) 14.5 MN·m/kg

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 5Zamak 7

Manufacturing and finishing

CapabilityZamak 5Zamak 7
Casting & forgingYes—
Default conditionAs CastAs Cast
Relative cost$ Budget$$ Standard
Min. machined wall——
Best machined surface——

Both are offered for CNC machining. Both take the same 6 finishes: Chrome Plating, Copper Plating, E-Coating, Nickel Plating, Painting, Powder Coating.

Zamak 5 vs Zamak 7 — frequently asked

Is Zamak 5 stronger than Zamak 7?

Yes. Zamak 5 has a typical yield strength of 268 MPa (38.9 ksi) against 210 MPa (30.5 ksi) for Zamak 7 — about 28% more. Tensile strength is 328 MPa (47.6 ksi) vs 283 MPa (41 ksi).

Which is cheaper, Zamak 5 or Zamak 7?

Zamak 5 is the lower-cost material: it sits in the budget tier ($) while Zamak 7 is standard ($$). 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 5 or Zamak 7?

Zamak 5. Its machinability rates excellent (85/100) against very good (80/100) for Zamak 7.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Zamak 5 and Zamak 7 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.