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Zinc Alloy Kirksite vs Zamak 3

Zinc Alloy · grade comparison

Zinc Alloy Kirksite and Zamak 3 are both zinc alloy grades. Zamak 3 is the stronger of the two: yield strength 221 MPa (32.1 ksi) against 190 MPa (27.6 ksi) for Kirksite, about 16% more; tensile strength follows at 283 MPa (41 ksi) vs 227 MPa (32.9 ksi). Zamak 3 is the more ductile: elongation 10% versus 3% for Kirksite, and Kirksite is harder (100 HB vs 82 HB). On the shop floor, Kirksite welds better (30 vs 20 out of 100) and Zamak 3 sits in a lower cost tier (budget, $) than Kirksite (premium, $$$).

KirksiteChoose it when it will be welded.

Zamak 3Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Kirksite vs Zamak 3: properties

KirksiteZamak 3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

37 GPa5.4 Msi
38 GPa5.5 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
221 MPa32.1 ksi

Elongation at Break

3%
10%

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
48 MPa7 ksi

Charpy V-Notch Impact (RT)

6 J4.4 ft·lbf
58 J42.8 ft·lbf

Hardness, Brinell

100 HB
82 HB

Hardness, Rockwell B

55 HRB
—

Hardness, Vickers

105 HV
—

Same in both: Elastic (Young's) Modulus 96 GPa13.9 Msi · Bulk Modulus 70 GPa10.2 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

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 · Max Service Temperature (continuous) 100°C212 °F · 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).

Corrosion Resistance

35 / 100
40 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -1 V

Manufacturability

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

Machinability

85 / 100
90 / 100

Machinability Rating (AISI 1212 = 100 %)

75%
120%

Weldability

30 / 100
20 / 100

Formability (cold)

15 / 100
20 / 100

Castability

92 / 100
97 / 100

Brazeability / Solderability

40 / 100
65 / 100

Polishability

65 / 100
85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

3.5 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

180 L/kg21.6 gal/lb
150 L/kg18 gal/lb

Typical Recycled Content

70%
25%

Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb

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
254 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 3Kirksite

Manufacturing and finishing

CapabilityKirksiteZamak 3
CNC machining—Yes
Casting & forging—Yes
Default condition—As Cast
Relative cost$$$ Premium$ Budget
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 3 — frequently asked

Is Zamak 3 stronger than Kirksite?

Yes. Zamak 3 has a typical yield strength of 221 MPa (32.1 ksi) against 190 MPa (27.6 ksi) for Kirksite — about 16% more. Tensile strength is 283 MPa (41 ksi) vs 227 MPa (32.9 ksi).

Which is cheaper, Kirksite or Zamak 3?

Zamak 3 is the lower-cost material: it sits in the budget 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 3?

Zamak 3, by a small margin. Both rate excellent for machinability — 90/100 against 85/100 for Kirksite; for welding the order is Kirksite first (poor, 30/100) then Zamak 3 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Kirksite and Zamak 3 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.