Zamak 2
Zamak 2 has the same composition as zamak 3 with the addition of 3% copper in order to increase strength by 20%, which also increases the price. Zamak 2 has the greatest strength out of all the zamak alloys. Over time it retains its strength and hardness better than the other alloys; however, it becomes more brittle, shrinks, and less elastic.
Zamak 2 is also known as Kirksite when gravity cast for use as a die. It was originally designed for low volume sheet metal dies. It later gained popularity for making short run injection molding dies. It is also less commonly used for non-sparking tools and mandrels for metal spinning.
| Alloying elements | Impurities | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Standard | Limit | Al | Cu | Mg | Pb | Cd | Sn | Fe | Ni | Si | In | Tl |
| ASTM B240 (Ingot) | min | 3.9 | 2.6 | 0.025 | - | - | - | - | - | - | - | - |
| max | 4.3 | 2.9 | 0.05 | 0.004 | 0.003 | 0.002 | 0.075 | - | - | - | - | |
| ASTM B86 (Cast) | min | 3.5 | 2.6 | 0.025 | - | - | - | - | - | - | - | - |
| max | 4.3 | 2.9 | 0.05 | 0.005 | 0.004 | 0.003 | 0.1 | - | - | - | - | |
| EN1774 (Ingot) | min | 3.8 | 2.7 | 0.035 | - | - | - | - | - | - | - | - |
| max | 4.2 | 3.3 | 0.06 | 0.003 | 0.003 | 0.001 | 0.02 | 0.001 | 0.02 | - | - | |
| EN12844 (Cast) | min | 3.7 | 2.7 | 0.025 | - | - | - | - | - | - | - | - |
| max | 4.3 | 3.3 | 0.06 | 0.005 | 0.005 | 0.002 | 0.05 | 0.02 | 0.03 | - | - | |
| GB8738-88 | min | 3.9 | 2.6 | 0.03 | - | - | - | - | - | - | - | - |
| max | 4.3 | 3.1 | 0.06 | 0.004 | 0.003 | 0.0015 | 0.035 | - | - | - | - | |
| Property | Metric value | English value |
|---|---|---|
| Mechanical properties | ||
| Ultimate tensile strength | 397 MPa (331 MPa aged) | 58,000 psi |
| Yield strength (0.2% offset) | 361 MPa | 52,000 psi |
| Impact strength | 38 J (7 J aged) | 28 ft-lbf (5 ft-lbf aged) |
| Elongation at Fmax | 3% (2% aged) | |
| Elongation at fracture | 6% | |
| Shear strength | 317 MPa | 46,000 psi |
| Compressive yield strength | 641 MPa | 93,000 psi |
| Fatigue strength (reverse bending 5x108 cycles) | 59 MPa | 8,600 psi |
| Hardness | 130 Brinell (98 Brinell aged) | |
| Modulus of elasticity | 96 GPa | 14,000,000 psi |
| Physical properties | ||
| Solidification range (melting range) | 379—390 °C | 714—734 °F |
| Density | 6.8 kg/dm3 | 0.25 lb/in3 |
| Coefficient of thermal expansion | 27.8 μm/m-°C | 15.4 μin/in-°F |
| Thermal conductivity | 105 W/m-K | 729 BTU-in/hr-ft2-°F |
| Electrical resistivity | 6.85 μΩ-cm at 20 °C | 2.70 μΩ-in at 68 °F |
| Latent heat (heat of fusion) | 110 J/g | 4.7x10−5 BTU/lb |
| Specific heat capacity | 419 J/kg-°C | 0.100 BTU/lb-°F |
| Coefficient of friction | 0.08 | |
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