Product Code Database
ZAMAK (or Zamac, formerly as MAZAK) is an eclectic family of with a base metal of zinc and alloying elements of aluminium, magnesium, and copper.
Zamak alloys are part of the zinc aluminum alloy family; they are distinguished from the other ZA alloys because of their constant 4% aluminium composition.
The name zamak is an acronym of the German language names for the metals of which the alloys are composed: Zink (zinc), Aluminium, Magnesium and Kupfer (copper). The New Jersey Zinc Company developed zamak alloys in 1929.
The most common zamak alloy is zamak 3. Besides that, zamak 2, zamak 5 and zamak 7 are also commercially used. These alloys are most commonly die cast. Zamak alloys (particularly #3 and #5) are frequently used in the spin casting industry.
A large problem with early zinc die casting materials was zinc pest, owing to impurities in the alloys. Zamak avoided this by the use of 99.99% pure zinc metal, produced by New Jersey Zinc's use of a as part of the Zinc refining process.
Zamak can be electroplated, wet painted, and chromate conversion coated well.
Zamak goes by many different names based on standard and/or country:
The short European designation code breaks down as follows (using ZL0430 as the example):
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..Parker, Dana T. Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II, p. 86, 119, 120, Cypress, CA, 2013. . It later gained popularity for making short run injection molding dies. It is also less commonly used for non-sparking tools and for metal spinning.
Mazak
In the early 1930s, Morris Ashby in Britain had licensed the New Jersey zamak alloy. The 99.99%-purity refluxer zinc was not available in Britain and so they acquired the right to manufacture the alloy using a locally available electrolytically refined zinc of 99.95% purity. This was given the name Mazak, partly to distinguish it from zamak and partly from the initials of Morris Ashby. In 1933, National Smelting licensed the refluxer patent with the intent of using it to produce 99.99% zinc in their plant at Avonmouth.
Standards
Zinc alloy chemical composition standards are defined per country by the standard listed below:
+ Zinc alloy standards per country. Europe EN1774 EN12844 US ASTM B240 ASTM B86 Japan JIS H2201 JIS H5301 Australia AS 1881 - SAA H63 AS 1881 - SAA H64 China GB 8738-88 - Canada CSA HZ3 CSA HZ11 International ISO 301 -
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 is less elastic.
+ Zamak 2 composition per standard
! colspan=2 ! colspan=3Alloying elements
! colspan=8 Impurities 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 - - - - + Zamak 2 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 scale (98 Brinell aged) Modulus of elasticity 96 GPa 14,000,000 psi 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
KS
The KS alloy was developed for spin casting decorative parts. It has the same composition as zamak 2, except with more magnesium in order to produce finer grains and reduce the orange peel effect.
+ KS composition
! colspan=2 ! colspan=3Alloying elements
! colspan=8 Impurities Nyrstar min 3.8 2.5 0.4 - - - - - - - - max 4.2 3.5 0.6 0.003 0.003 0.001 0.020 - - - -
Zamak 3
Zamak 3 is the de facto standard for the zamak series of zinc alloys; all other zinc alloys are compared to this. Zamak 3 has the base composition for the zamak alloys (96% zinc, 4% aluminum). It has excellent castability and long term dimensional stability. More than 70% of all North American zinc die castings are made from zamak 3.
+ Zamak 3 composition per standard
! colspan=2 ! colspan=3Alloying elements
! colspan=8 Impurities ASTM B240 (Ingot) min 3.9 - 0.025 - - - - - - - - max 4.3 0.1 0.05 0.004 0.003 0.002 0.035 - - - - ASTM B86 (Cast) min 3.5 - 0.025 - - - - - - - - max 4.3 0.25 0.05 0.005 0.004 0.003 0.1 - - - - EN1774 (Ingot) min 3.8 - 0.035 - - - - - - - - max 4.2 0.03 0.06 0.003 0.003 0.001 0.02 0.001 0.02 - - EN12844 (Cast) min 3.7 - 0.025 - - - - - - - - max 4.3 0.1 0.06 0.005 0.005 0.002 0.05 0.02 0.03 - - JIS H2201 (Ingot) min 3.9 - 0.03 - - - - - - - - max 4.3 0.03 0.06 0.003 0.002 0.001 0.075 - - - - JIS H5301 (Cast) min 3.5 - 0.02 - - - - - - - - max 4.3 0.25 0.06 0.005 0.004 0.003 0.01 - - - - AS1881 min 3.9 - 0.04 - - - - - - - - max 4.3 0.03 0.06 0.003 0.003 0.001 0.05 - 0.001 0.0005 0.001 GB8738-88 min 3.9 - 0.03 - - - - - - - - max 4.3 0.1 0.06 0.004 0.003 0.0015 0.035 - - - - †Impurity
Zamak 4
Zamak 4 was developed for the Asian markets to reduce the effects of die soldering while maintaining the ductility of zamak 3. This was achieved by using half the amount of copper from the zamak 5 composition.
+ Zamak 4 composition per standard
! colspan=2 ! colspan=3Alloying elements
! colspan=8 Impurities Ningbo Jinyi Alloy Material Co. min 3.9 0.3 0.03 - - - - - - - - max 4.3 0.5 0.06 0.003 0.002 0.002 0.075 - - - - + Zamak 4 properties Ultimate tensile strength 317 MPa 46,000 psi Yield strength (0.2% offset) 221—269 MPa 32,000—39,000 psi Impact strength 61 J (7 J aged) 45 ft-lbf (5 ft-lbf aged) Elongation 7% Shear strength 214—262 MPa 31,000—38,000 psi Compressive yield strength 414—600 MPa 60,000—87,000 psi Fatigue strength (rotary bending 5x108 cycles) 48—57 MPa 7,000—8,300 psi Hardness 91 Brinell Solidification range (melting range) 380—386 °C 716—727 °F Density 6.6 g/cm3 0.24 lb/in3 Coefficient of thermal expansion 27.4 μm/m-°C 15.2 μin/in-°F Thermal conductivity 108.9—113.0 W/m-K @ 100 °C 755.6—784.0 BTU-in/hr-ft2-°F @ 212 °F Electrical conductivity 26-27% IACS Specific heat capacity 418.7 J/kg-°C 0.100 BTU/lb-°F
Zamak 5
Zamak 5 has the same composition as zamak 3 with the addition of 1% copper in order to increase strength (by approximately 10%), hardness and corrosive resistance, but reduces ductility. It also has less dimensional accuracy. Zamak 5 is more commonly used in Europe.
+ Zamak 5 composition per standard
! colspan=2 ! colspan=3Alloying elements
! colspan=8 Impurities ASTM B240 (Ingot) min 3.9 0.75 0.03 - - - - - - - - max 4.3 1.25 0.06 0.004 0.003 0.002 0.075 - - - - ASTM B86 (Cast) min 3.5 0.75 0.03 - - - - - - - - max 4.3 1.25 0.06 0.005 0.004 0.003 0.1 - - - - EN1774 (Ingot) min 3.8 0.7 0.035 - - - - - - - - max 4.2 1.1 0.06 0.003 0.003 0.001 0.02 0.001 0.02 - - EN12844 (Cast) min 3.7 0.7 0.025 - - - - - - - - max 4.3 1.2 0.06 0.005 0.005 0.002 0.05 0.02 0.03 - - JIS H2201 (Ingot) min 3.9 0.75 0.03 - - - - - - - - max 4.3 1.25 0.06 0.003 0.002 0.001 0.075 - - - - JIS H5301 (Cast) min 3.5 0.75 0.02 - - - - - - - - max 4.3 1.25 0.06 0.005 0.004 0.003 0.01 - - - - AS1881 min 3.9 0.75 0.04 - - - - - - - - max 4.3 1.25 0.06 0.003 0.003 0.001 0.05 - 0.001 0.0005 0.001 GB8738-88 min 3.9 0.7 0.03 - - - - - - - - max 4.3 1.1 0.06 0.004 0.003 0.0015 0.035 - - - -
Zamak 7
Zamak 7 has less magnesium than zamak 3 to increase fluidity and ductility, which is especially useful when casting thin wall components. In order to reduce inter-granular corrosion a small amount of nickel is added and impurities are more strictly controlled.
+ Zamak 7 composition per standard
! colspan=2 ! colspan=3Alloying elements
! colspan=8 Impurities ASTM B240 (Ingot) min 3.9 - 0.01 - - - - - - - - max 4.3 0.1 0.02 0.002 0.002 0.001 0.075 - - - - ASTM B86 (Cast) min 3.5 - 0.005 - - - - 0.005 - - - max 4.3 0.25 0.02 0.003 0.002 0.001 0.075 0.02 - - - GB8738-88 min 3.9 - 0.01 - - - - 0.005 - - - max 4.3 0.1 0.02 0.002 0.002 0.001 0.075 0.02 - - - †Impurity ‡Alloying element
Uses
Common uses for zamak alloys include appliances, bathroom fixtures, die cast toys and automotive industry. Zamak alloys are also used in the manufacture of some firearms such as those from Hi-Point Firearms. In World War 2, zamak alloy buttplates were one of three variations common on Canadian and American-made .303 Lee Enfield rifles, particularly during mid-war production.Charles R. Stratton, British Enfield Rifles, Vol 2, North Cape Publications, 1999 and 2003, pages 106-107
See also
External links
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