FabDigitFabDigit

Zinc Alloy Kirksite vs Zamak 7

Zinc Alloy · grade comparison

Zinc Alloy Kirksite and Zamak 7 are both zinc alloy grades. Zamak 7 is the stronger of the two: yield strength 210 MPa (30.5 ksi) against 190 MPa (27.6 ksi) for Kirksite, about 11% more; tensile strength follows at 283 MPa (41 ksi) vs 227 MPa (32.9 ksi). Zamak 7 is the more ductile: elongation 13% versus 3% for Kirksite, and Kirksite is harder (100 HB vs 80 HB). On the shop floor, Kirksite welds better (30 vs 15 out of 100) and Zamak 7 sits in a lower cost tier (standard, $$) than Kirksite (premium, $$$).

KirksiteChoose it when it will be welded.

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

Kirksite vs Zamak 7: properties

KirksiteZamak 7

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

70 GPa10.2 Msi
—

Poisson's Ratio

0.3
0.27

Tensile Strength (Ultimate)

227 MPa32.9 ksi
283 MPa41 ksi

Yield Strength (0.2% offset)

190 MPa27.6 ksi
210 MPa30.5 ksi

Elongation at Break

3%
13%

Compressive Strength

415 MPa60.2 ksi
414 MPa60 ksi

Shear Strength

180 MPa26.1 ksi
214 MPa31 ksi

Fatigue Strength (Endurance Limit)

55 MPa8 ksi
47 MPa6.8 ksi

Charpy V-Notch Impact (RT)

6 J4.4 ft·lbf
58 J42.8 ft·lbf

Hardness, Brinell

100 HB
80 HB

Hardness, Rockwell B

55 HRB
41 HRB

Hardness, Vickers

105 HV
84 HV

Same in both: Elastic (Young's) Modulus 96 GPa13.9 Msi · Shear Modulus 37 GPa5.4 Msi

Physical

Density and transition temperatures.

Density

6.7 g/cm³0.24 lb/in³
6.6 g/cm³0.24 lb/in³

Melting Point (Solidus)

379°C714 °F
381°C718 °F

Liquidus Temperature

390°C734 °F
387°C729 °F

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

6.6×10⁻⁸ Ω·m2.6 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

35 / 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 %)

75%
80%

Weldability

30 / 100
15 / 100

Formability (cold)

15 / 100
35 / 100

Castability

92 / 100
97 / 100

Brazeability / Solderability

40 / 100
75 / 100

Polishability

65 / 100
85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

180 L/kg21.6 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

70%
25%

Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 3.5 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

34 kN·m/kg
43 kN·m/kg

Specific Stiffness (E / density)

14.3 MN·m/kg
14.5 MN·m/kg

Modulus of Resilience

188 kJ/m³
230 kJ/m³

Thermal Diffusivity

38.8 mm²/s
40.9 mm²/s

Thermal Shock Resistance Index

9
12

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 7Kirksite

Manufacturing and finishing

CapabilityKirksiteZamak 7
CNC machining—Yes
Default condition—As Cast
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——
Chrome Plating—Yes
E-Coating—Yes
Nickel Plating—Yes
Painting—Yes
Powder Coating—Yes

They share 1 finish: Copper Plating.

Kirksite vs Zamak 7 — frequently asked

Is Zamak 7 stronger than Kirksite?

Yes. Zamak 7 has a typical yield strength of 210 MPa (30.5 ksi) against 190 MPa (27.6 ksi) for Kirksite — about 11% more. Tensile strength is 283 MPa (41 ksi) vs 227 MPa (32.9 ksi).

Which is cheaper, Kirksite or Zamak 7?

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

Kirksite. Its machinability rates excellent (85/100) against very good (80/100) for Zamak 7; for welding the order is Kirksite first (poor, 30/100) then Zamak 7 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Kirksite 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.