Zamak

Zamak ingot

Zamak (formerly trademarked as ZAMAK^[1] and also known as Zamac) 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.^[2]

The name zamak is an acronym of the German names for the metals of which the alloys are composed: Zink (zinc), Aluminium, Magnesium and Kupfer (copper).^[2] The New Jersey Zinc Company developed zamak alloys in 1929. Zinc alloys are popularly referred to as pot metal or white metal. While zamak is held to higher industrial standards, it is still considered a pot metal.

The most common zamak alloy is zamak 3. Besides that, zamak 2, zamak 5 and zamak 7 are also commercially used.^[2] These alloys are most commonly die cast.^[2] 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.^[3] 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 smelting process.

Zamak can be electroplated, wet painted, and chromate conversion coated well.^[4]

Mazak

In the early 1930s Morris Ashby in Britain had licensed the New Jersey zamak alloy. The high-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.^[5]

Standards

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

Zinc alloy standards per country^[6]

Country	Zinc ingot	Zinc casting
Europe	EN1774	EN12844
USA	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[7]	France NFA 55-010[7]	Germany DIN 1743-2[7]	UNS	Other
Zamak 2[8][9] or Kirksite[10]	ZnAl4Cu3[11]	Ingot	Alloy 2[8][9]	AC 43A[8][9]	ZL0430[11]	-	ZX04[12]	-	Z-A4U3[11]	Z430[11]	Z35540[9]	ZL2, ZA-2, ZN-002[13]
		Cast			ZP0430		-				Z35541[8]	ZP2, ZA-2, ZN-002[13]
Zamak 3[8][9]	ZnAl4[11]	Ingot	Alloy 3[8][9]	AG 40A[8][9]	ZL0400[11]	Ingot type 2[14]	ZX01[12]	Alloy A[11]	Z-A4[11]	Z400[11]	Z35521[9]	ZL3, ZA-3, ZN-003[13]
		Cast			ZP0400	ZDC2[15]	-				Z33520[8]	ZP3, ZA-3, ZN-003[13]
Zamak 4[16]		Ingot	Used in Asia only									ZA-4, ZN-004[13]
Zamak 5[8][9]	ZnAl4Cu1[11]	Ingot	Alloy 5[8][9]	AC 41A[8][9]	ZL0410[11]	Ingot type 1[14]	ZX03[12]	Alloy B[11]	Z-A4UI[11]	Z410[11]	Z35530[9]	ZL5, ZA-5, ZN-005[13]
		Cast			ZP0410	ZDC1[15]	-				Z35531[8]	ZP5, ZA-5, ZN-005[13]
Zamak 7[8][9]	ZnAl4Ni[12]	Ingot	Alloy 7[8][9]	AG 40B[8][9]	-	-	ZX02[12]	-	-	-	Z33522[9]	ZA-7, ZN-007[13]
		Cast					-				Z33523[8]
^†color of the cell is the color of the material designated by ASTM B908.[2]

The Short European Designation code breaks down as follows (using ZL0430 as the example):^[11]

• Z is the material (Z=Zinc)
• P is the use (P=Pressure die casting (casting), L=Ingot)
• 04 is the percent aluminium (04= 4% aluminium)
• 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 less elastic.^[17]

Zamak 2 is also known as Kirksite when gravity cast for use as a die.^[2][18] It was originally designed for low volume sheet metal dies.^[19][20] It later gained popularity for making short run injection molding dies.^[19] It is also less commonly used for non-sparking tools and mandrels for metal spinning.

Zamak 2 composition per standard

		Alloying elements			Impurities
Standard	Limit	Al	Cu	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl
ASTM B240[21] (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[22] (Cast)	min	3.5	2.6	0.025	-	-	-	-	-	-	-	-
	max	4.3	2.9	0.05	0.005	0.004	0.003	0.1	-	-	-	-
EN1774[23] (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[24] (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[12]	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^[17]

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.^[25]

KS composition^[25]

		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^[25]

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% aluminium). It has excellent castability and long term dimensional stability. More than 70% of all North American zinc die castings are made from zamak 3.^[2]

Zamak 3 composition per standard

		Alloying elements			Impurities
Standard	Limit	Al	Cu^†	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl
ASTM B240[21] (Ingot)	min	3.9	-	0.025	-	-	-	-	-	-	-	-
	max	4.3	0.1	0.05	0.004	0.003	0.002	0.075	-	-	-	-
ASTM B86[22] (Cast)	min	3.5	-	0.025	-	-	-	-	-	-	-	-
	max	4.3	0.25	0.05	0.005	0.004	0.003	0.1	-	-	-	-
EN1774[23] (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[24] (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[14] (Ingot)	min	3.9	-	0.03	-	-	-	-	-	-	-	-
	max	4.3	0.03	0.06	0.003	0.002	0.001	0.075	-	-	-	-
JIS H5301[15] (Cast)	min	3.5	-	0.02	-	-	-	-	-	-	-	-
	max	4.3	0.25	0.06	0.005	0.004	0.003	0.01	-	-	-	-
AS1881[26]	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[12]	min	3.9	-	0.03	-	-	-	-	-	-	-	-
	max	4.3	0.1	0.06	0.004	0.003	0.0015	0.035	-	-	-	-
^†Impurity

Zamak 3 properties^[4]

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.^[27]

Zamak 4 composition per standard

		Alloying elements			Impurities
Standard	Limit	Al	Cu	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl
Ningbo Jinyi Alloy Material Co.[13]	min	3.9	0.3	0.03	-	-	-	-	-	-	-	-
	max	4.3	0.5	0.06	0.003	0.002	0.002	0.075	-	-	-	-
Genesis Alloys Ltd.[28]	min	3.9	0.3	0.04	-	-	-	-	-	-	-	-
	max	4.2	0.4	0.05	0.003	0.002	0.001	0.02	0.001	0.02	0.0005	0.001

Zamak 4 properties

Property	Metric value	Imperial value
Mechanical properties[29]
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[30]
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%^[17]), hardness and corrosive resistance, but reduces ductility.^[31] It also has less dimensional accuracy.^[31] Zamak 5 is more commonly used in Europe.^[2]

Zamak 5 composition per standard

		Alloying elements			Impurities
Standard	Limit	Al	Cu	Mg	Pb	Cd	Sn	Fe	Ni	Si	In	Tl	Zn
ASTM B240[21] (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[22] (Cast)	min	3.5	0.75	0.03	-	-	-	-	-	-	-	-
	max	4.3	1.25	0.06	0.005	0.004	0.003	0.1	-	-	-	-
EN1774[23] (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[24] (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[14] (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[15] (Cast)	min	3.5	0.75	0.02	-	-	-	-	-	-	-	-
	max	4.3	1.25	0.06	0.005	0.004	0.003	0.01	-	-	-	-
AS1881[26]	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[12]	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^[31]

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.^[2]

Zamak 7 composition per standard

		Alloying elements			Impurities
Standard	Limit	Al	Cu^†	Mg	Pb	Cd	Sn	Fe	Ni^‡	Si	In	Tl
ASTM B240[21] (Ingot)	min	3.9	-	0.01	-	-	-	-	-	-	-	-
	max	4.3	0.1	0.02	0.002	0.002	0.001	0.075	-	-	-	-
ASTM B86[22] (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[12]	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^[32]

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:^[33]

• Blenders
• Mirror frames
• Plumbing fittings
• Zippers
• Bathroom fixtures (faucets and shower heads)
• Rickenbacker guitar "R" tailpieces
• Gibson Tune-o-Matic bridge and stopbar tailpiece
• Staplers
• Safety razors (most modern mass-market production)
• Handles
• Locks
• Die-cast toys^[34]
• Sheet metal tooling^[18]
• Automotive parts^[34]
• Ceiling fans^[34]
• Golf clubs^[34]
• Fishing reels^[34]
• Wheel balancing weights (especially prominent in the European Union)

Zamak alloys are also used in firearms, including those manufactured by:

• Gyrojet
• Hi-Point Firearms
• Raven Arms
• Jimenez Arms
• Sundance Industries
• Lorcin Engineering Company
• Arcadia Machine & Tool
• Davis Industries
• Phoenix Arms
• Henry Repeating Arms - Lever Action .22lr Receiver Covers

References

1. Zamak Latest Status Info, retrieved 2008-03-02
2. Diecasting Alloys, retrieved 2008-03-02
3. Wanhill, R.J.H.; Hattenberg, T. (May 2005), Corrosion-induced cracking of model train zinc-aluminium die castings (PDF), National Aerospace Laboratory NLR, NLR-TP-2005-205, archived from the original (PDF) on 2011-07-16.
4. ZL3/ZL0400/ZnAl4 (Zamak 3), retrieved 2008-02-29
5. Cocks, E.J.; Walters, B. (1968), A History of the Zinc Smelting Industry in Britain, Harrap, ISBN 0 245 59377 2.
6. World wide zinc die casting standards, Nyrstar, retrieved 2008-02-25.
7. Now defunct due to standardization of European countries under EN 1774 & EN 12844.
8. ASTM B86-04e2, 2004-10-01, retrieved 2008-02-10
9. ASTM B240-98, 1998-05-01, retrieved 2008-02-10
10. prepared under the direction of the ASM International Handbook Committee ; S.L. Semiatin, volume éditor. (1990), ASM Handbook, 14B, ASM International Handbook Committee, ISBN 0-87170-710-1.
11. Alloy designation - cross reference table, archived from the original (PDF) on 2010-10-31, retrieved 2010-10-31
12. GB8738 - Chinese standard: zinc alloys ingots for casting (2006), retrieved 2008-02-27
13. ZN-004, retrieved 2008-03-01
14. JIS H2201 - Japanese Industrial Standard - Zinc alloy ingot for die casting (1999), retrieved 2008-02-26
15. JIS H5301 - Japanese Industrial Standard - Zinc alloy die casting (1979), retrieved 2008-02-26
16. zamak 4 (Alloy 4), retrieved 2008-03-01
17. ZL2/ZL0430/ZnAl4Cu3 (Zamak 2), retrieved 2008-02-29
18. Husite Engineering - Benefits of Cast Kirksite Tooling, retrieved April 19, 2011
19. Armstrong, Paul J.; Petch, Bill, Cast Kirksite Re-Emerges as RT Approach for Molding Plastics, retrieved 2008-03-15.
20. Parker, Dana T. Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II, p. 86, 119, 120, Cypress, CA, 2013. ISBN 978-0-9897906-0-4.
21. ASTM B240: Standard specification for zinc in ingot form for die casting: chemical composition, retrieved 2008-02-27
22. ASTM B86: Standard specification for zinc die casting: chemical composition, retrieved 2008-02-27
23. EN1774 Standard - zinc and zinc alloys - alloys for foundry purposes - ingot and liquid, retrieved 2008-02-27
24. EN12844: Standard - zinc and zinc alloys - castings - specification (September 1998), retrieved 2008-02-27
25. KS (spin casting alloy), retrieved 2008-03-15
26. AS1881 - Australia standard - Zinc alloys - casting ingots and casting requirements (1986), retrieved 2008-02-27
27. zamak 4 (Alloy 4), retrieved 2008-03-09
28. Genesis Alloy 4, retrieved 2008-03-01
29. Zinc alloy mechanical characteristics, retrieved 2008-03-01
30. Zinc alloy physical characteristics, retrieved 2008-03-01
31. ZL5/ZL0410/ZnAl4Cu1 (Zamak 5), retrieved 2008-02-29
32. Zinc Alloy 7; AG40B; Zn-4Al-0.015Mg, retrieved 2008-02-29
33. Peñoles zamak, retrieved 2008-03-02
34. Zinc alloy various purposes, retrieved 2008-03-02

External links

• Generic Terms For Zinc Alloys