Zamak Explained

ZAMAK (or Zamac, formerly trademarked as MAZAK) is a family of alloys with a base metal of zinc and alloying elements of aluminium, magnesium, and copper.

Zamak alloys are part of the zinc aluminium 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 names for the metals of which the alloys are composed: German: Zink (zinc), German: Aluminium, German: Magnesium and German: 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 refluxer as part of the refining process.

Zamak can be electroplated, wet painted, and chromate conversion coated well.

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. It is colloquially known among UK car restoration hobbyists as monkey metal.

Standards

Zinc alloy chemical composition standards are defined per country by the standard listed below:

Zinc alloy standards per country^[1]

Country	Zinc ingot	Zinc casting
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 goes by many different names based on standard and/or country:

Various names for zamak alloys

Traditional name	Short composition name	Form	Common	ASTM^†	Short European designation	JIS	China	UK BS 1004^[2]	France NFA 55-010	Germany DIN 1743-2	UNS	Other
Zamak 2 or Kirksite^[3]	ZnAl4Cu3	Ingot	Alloy 2	AC 43A	ZL0430	-	ZX04	-	Z-A4U3	Z430	Z35540	ZL2, ZA-2, ZN-002
		Cast		ZP0430	-		Z35541				ZP2, ZA-2, ZN-002
Zamak 3	ZnAl4	Ingot	Alloy 3	AG 40A	ZL0400	Ingot type 2	ZX01	Alloy A	Z-A4	Z400	Z35521	ZL3, ZA-3, ZN-003
		Cast		ZP0400	ZDC2	-	Z33520				ZP3, ZA-3, ZN-003
Zamak 4		Ingot	Used in Asia only									ZA-4, ZN-004
Zamak 5	ZnAl4Cu1	Ingot	Alloy 5	AC 41A	ZL0410	Ingot type 1	ZX03	Alloy B	Z-A4UI	Z410	Z35530	ZL5, ZA-5, ZN-005
		Cast		ZP0410	ZDC1	-	Z35531				ZP5, ZA-5, ZN-005
Zamak 7	ZnAl4Ni	Ingot	Alloy 7	AG 40B	-	-	ZX02	-	-	-	Z33522	ZA-7, ZN-007
		Cast		-			Z33523
^†color of the cell is the color of the material designated by ASTM B908.

The Short European Designation code breaks down as follows (using ZL0430 as the example):

• Z is the material (Z=Zinc)
• P is the use (P=Pressure die casting (casting), L=Ingot)
• 04 is the percent aluminum (04= 4% aluminum)
• 3 is the percent copper (3= 3% copper)

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 is also known as Kirksite when gravity cast for use as a die. It was originally designed for low volume sheet metal dies.^{[4] [5]} It later gained popularity for making short run injection molding dies.^[4] It is also less commonly used for non-sparking tools and mandrels for metal spinning.

! colspan=3

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	-	-	-	-

Zamak 2 properties

Property	Metric value	Imperial 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 5x10^8 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/dm^3	0.25 lb/in^3
Coefficient of thermal expansion	27.8 μm/m-°C	15.4 μin/in-°F
Thermal conductivity	105 W/m-K	729 BTU-in/hr-ft^2-°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.

! colspan=3

Alloying elements	Impurities
Standard	Limit	Al	Cu	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl
Nyrstar	min	3.8	2.5	0.4	-	-	-	-	-	-	-	-
	max	4.2	3.5	0.6	0.003	0.003	0.001	0.020	-	-	-	-

KS properties

Property	Metric value	Imperial value
Mechanical properties
Ultimate tensile strength	< 200 MPa	< 29,000 psi
Yield strength (0.2% offset)	< 200 MPa	< 29,000 psi
Elongation	< 2%
Hardness	150 Brinell max
Physical properties
Solidification range (melting range)	380—390 °C	716—734 °F
Density	6.6 g/cm^3	0.25 lb/in^3
Coefficient of thermal expansion	28.0 μm/m-°C	15.4 μin/in-°F
Thermal conductivity	105 W/m-K	729 BTU-in/hr-ft^2-°F
Electrical conductivity	25% IACS
Specific heat capacity	419 J/kg-°C	0.100 BTU/lb-°F
Coefficient of friction	0.08

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.

! colspan=3

Alloying elements	Impurities
Standard	Limit	Al	Cu^†	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl
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 3 properties

Property	Metric value	Imperial value
Mechanical properties
Ultimate tensile strength	268 MPa	38,900 psi
Yield strength (0.2% offset)	208 MPa	30,200 psi
Impact strength	46 J (56 J aged)	34 ft-lbf (41 ft-lbf aged)
Elongation at Fmax	3%
Elongation at fracture	6.3% (16% aged)
Shear strength	214 MPa	31,000 psi
Compressive yield strength	414 MPa	60,000 psi
Fatigue strength (reverse bending 5x10^8 cycles)	48 MPa	7,000 psi
Hardness	97 Brinell
Modulus of elasticity	96 GPa	14,000,000 psi
Physical properties
Solidification range (melting range)	381—387 °C	718—729 °F
Density	6.7 g/cm^3	0.24 lb/in^3
Coefficient of thermal expansion	27.4 μm/m-°C	15.2 μin/in-°F
Thermal conductivity	113 W/mK	784 BTU-in/hr-ft^2-°F
Electrical resistivity	6.37 μΩ-cm at 20 °C	2.51 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	0.07

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.

! colspan=3

Alloying elements	Impurities
Standard	Limit	Al	Cu	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl
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

Property	Metric value	Imperial value
Mechanical properties^[6]
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 5x10^8 cycles)	48—57 MPa	7,000—8,300 psi
Hardness	91 Brinell
Physical properties^[7]
Solidification range (melting range)	380—386 °C	716—727 °F
Density	6.6 g/cm^3	0.24 lb/in^3
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-ft^2-°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.

! colspan=3

Alloying elements	Impurities
Standard	Limit	Al	Cu	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl	Zn
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 5 properties

Property	Metric value	Imperial value
Mechanical properties
Ultimate tensile strength	331 MPa (270 MPa aged)	48,000 psi (39,000 psi aged)
Yield strength (0.2% offset)	295 MPa	43,000 psi
Impact strength	52 J (56 J aged)	38 ft-lbf (41 ft-lbf aged)
Elongation at Fmax	2%
Elongation at fracture	3.6% (13% aged)
Shear strength	262 MPa	38,000 psi
Compressive yield strength	600 MPa	87,000 psi
Fatigue strength (reverse bending 5x10^8 cycles)	57 MPa	8,300 psi
Hardness	91 Brinell
Modulus of elasticity	96 GPa	14,000,000 psi
Physical properties
Solidification range (melting range)	380—386 °C	716—727 °F
Density	6.7 kg/dm^3	0.24 lb/in^3
Coefficient of thermal expansion	27.4 μm/m-°C	15.2 μin/in-°F
Thermal conductivity	109 W/mK	756 BTU-in/hr-ft^2-°F
Electrical resistivity	6.54 μΩ-cm at 20 °C	2.57 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

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.

! colspan=3

Alloying elements	Impurities
Standard	Limit	Al	Cu^†	Mg	Pb	Cd	Sn	Fe	Ni^‡	Si	In	Tl
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

Zamak 7 properties

Property	Metric value	Imperial value
Mechanical properties
Ultimate tensile strength	285 MPa	41,300 psi
Yield strength (0.2% offset)	285 MPa	41,300 psi
Impact strength	58.0 J	42.8 ft-lbf
Elongation at fracture	14%
Shear strength	214 MPa	31,000 psi
Compressive yield strength	414 MPa	60,000 psi
Fatigue strength (reverse bending 5x10^8 cycles)	47.0 MPa	6,820 psi
Hardness	80 Brinell
Physical properties
Solidification range (melting range)	381—387 °C	718—729 °F
Coefficient of thermal expansion	27.4 μm/m-°C	15.2 μin/in-°F
Thermal conductivity	113 W/m-K	784 BTU-in/hr-ft^2-°F
Electrical resistivity	6.4 μΩ-cm	2.5 μΩ-in
Specific heat capacity	419 J/kg-°C	0.100 BTU/lb-°F
Casting temperature	395—425 °C	743—797 °F

Uses

Common uses for zamak alloys include appliances, bathroom fixtures, die cast toys and automotive industry.^{[8] [9]} Zamak alloys are also used in the manufacture of some firearms such as those from Hi-Point Firearms.^{[10] [11]} 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.^[12]

See also

• Pot metal
• Babbitt (alloy)

External links

• Generic Terms For Zinc Alloys
• Zinc Die Casting Alloy Guide

Notes and References

1. .
2. Now defunct due to standardization of European countries under EN 1774 & EN 12844.
3. Book: Semiatin, S. L.. ASM Handbook, Volume 14B: Metalworking: Sheet Forming. 2006. ASM International. 978-0-87170-710-9. en.
4. .
5. Parker, Dana T. Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II, p. 86, 119, 120, Cypress, CA, 2013. .
6. https://www.eazall.com/PublicDoc/ZincDie%20CastingPropertiesGuide2012.pdf
7. https://www.eazall.com/PublicDoc/ZincDie%20CastingPropertiesGuide2012.pdf
8. Web site: Zamak is an alloy. 2023-08-26.
9. Web site: Zamak Alloys in the automotive industry.
10. Web site: SW380 - Forgotten Pocket Gun That Should Stay Thataway. 3 April 2019.
11. Web site: An Official Journal of the NRA | Pistol-Caliber Pairing: Hi-Point's Affordable Firearms.
12. Charles R. Stratton, British Enfield Rifles, Vol 2, North Cape Publications, 1999 and 2003, pages 106-107