|
Typical
Mechanical Properties
| |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
| Tensile
strength, psi x 1000 |
47
|
55
|
34
|
41
|
| Yield strength,
psi x 100 (0.2 pct offset) |
23
|
30
|
23
|
--
|
| Shear strength,
psi x 1000 |
28
|
37
|
20
|
31
|
| Fatigue
strength, psi x 1000 |
20
|
25
|
14
|
7
|
| Elongation,
pct in 2 in. |
3.50
|
15
|
3.0
|
10
|
| Hardness
(Brinell) |
80
|
91
|
63
|
82
|
| Specific
gravity |
2.71
|
8.30
|
1.80
|
6.60
|
| Weight,
lb/cu. in. |
.098
|
0.305
|
.066
|
0.24
|
| Melting
point (liquid), oF |
1100
|
1670
|
1105
|
728
|
| Thermal
conductivity, CGS |
0.23
|
0.21
|
0.16
|
0.27
|
| Thermal
expansion, in./in./oF x 10-6 |
12.1
|
12.0
|
15.0
|
15.2
|
| Electrical
conductivity, pct of copper standard |
27
|
20
|
10
|
27
|
| Modulus
of elasticity, psi x 106 |
10.3
|
15
|
6.5
|
--
|
| Impact strength
(Charpy), ft/lb |
3.0
|
40
|
2.0
|
43.0
|
For more specific
information, refer to NADCA Product Standards for Die Casting.
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Finishing:
Decorative
| |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
| Chrome
plating |
Fair |
Excellent |
Fair |
Excellent |
| Black
chrome plating |
Fair |
Excellent |
--
|
Excellent |
| Colored
plating |
Fair |
--
|
--
|
Excellent |
| Mechanical-polishing
& buffing |
Excellent |
Excellent |
Excellent |
Excellent |
| Lacquers,
enamels, epoxies & acrylics |
Excellent |
Excellent |
Excellent |
Excellent |
| Anodizing |
Fair |
--
|
--
|
--
|
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|
Protective
|
| |
|
|
|
|
| |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
| Anodizing-corrosion
& abrasion protection |
Excellent |
--
|
Good |
Excellent |
| Chromate
conversion-corrosion |
Excellent |
--
|
Excellent |
Excellent |
| Heavy
paint, wrinkle, matte finishes-abrasion, corrosion protection
& to hide imperfections |
Excellent |
Excellent |
Excellent |
Excellent |
NOTE:
This chart does not intend to compare metals. Its
purpose is to show the most satisfactory methods of
finishing each specific metal.
|
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|
Processing and
Production
|
| Machine
Types: |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
Hot
chamber (Plunger)
|
No
|
No
|
Yes
|
Yes
|
Cold
chamber
|
Yes
|
Yes
|
Yes
|
Yes
|
| Production
range, shots/hr |
40-200
|
40-200
|
75-400
|
200-550
|
| Average
tool life, no. of shots x 1000 |
125
|
20
|
200
|
500
|
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Chemical Composition
(%)
| |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
| Aluminum |
Remainder
|
0.25
|
8.3
to 9.7
|
3.5
to 4.3
|
| Cadmium |
--
|
--
|
--
|
.004
(max)
|
| Copper |
3.0
to 4.0
|
57.0
(min)
|
0.35
(max)
|
0.25
(max)
|
| Iron |
1.3
|
0.50
|
--
|
0.10
(max)
|
| Lead |
--
|
1.50
|
--
|
.005
(max)
|
| Magnesium |
0.10
|
--
|
Remainder
|
.02
to .05
|
| Manganese |
0.50
|
0.25
|
0.13
(min)
|
--
|
| Nickel |
0.50
|
--
|
.03
(max)
|
*
|
| Silicon |
7.5
to 9.5
|
0.25
(max)
|
0.5
(max)
|
*
|
| Tin |
0.35
|
1.50
|
--
|
.003
(max)
|
| Zinc |
3.0
|
Remainder
|
0.35
to 1.0
|
Remainder
|
| Other |
0.50
|
0.50
|
0.3
(max)
|
--
|
| Mechanical
properties and chemical composition vary for specific alloys.
Refer to NADCA Product Standards for Die Casting for details. |
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|
Characteristics of Die
Casting Alloys
|
| |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
| Dimensional
stability |
Good
|
Excellent
|
Excellent
|
Good
|
| Corrosion
resistance |
Good
|
Excellent
|
Fair
|
Fair
|
| Casting
ease |
Good
|
Fair
|
Good
|
Excellent
|
| Part
complexity |
Good
|
Fair
|
Good
|
Excellent
|
| Dimensional
accuracy |
Good
|
Fair
|
Excellent
|
Excellent
|
| Die
cost |
Medium
|
High
|
Medium
|
Low
|
| Machining
cost |
Low
|
Medium
|
Low
|
Low
|
| Finishing
cost |
Medium
|
Low
|
High
|
Low
|
Chart does not
intend to compare metals. Its purpose is to show the most advantageous
characteristics of each specific metal. For more specific information,
refer to NADCA Product Standards for Die Casting.
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Dimensional
and Weight Limits
| |
Aluminum
|
Brass
|
Magnesium
|
Zinc
|
| Maximum
weight, lb. |
70
|
10
|
44
|
75
|
| Minimum
wall thickness, large castings, in. |
.080
|
.090
|
.100
|
.035
|
| Minimum
wall thickness, small castings, in. |
.040
|
.055
|
.040
|
.015
|
| Minimum
variation per in. of diameter or length from drawing dimensions
over one in. |
.0015
|
.009
|
.0015
|
.001
|
| Cast
threads, max. per in. external |
24
|
10
|
24
|
32
|
| Cored
holes, min. diameter in. |
.080
|
0.250
|
.080
|
.050
|
The values shown
herein represent normal production practice at the most economic
level. Greater accuracy involving extra close work or care in production
should be specified only when and where necessary since additional
cost may be involved.
For more specific
information, refer to NADCA Product Standards for Die Casting.
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|
