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Sand casting is the simplest and most versatile of all casting processes used to produce castings. This process uses wooden or metal patterns that are then | placed in the split moulding frame. The frame is then filled with sand and packed around the pattern. The mould is then separated and the pattern removed. Once the mould halves are reassembled, the resulting cavity is filled with the selected molten alloy. There are a variety of types of sand casting, including chemically bonded, clay bonded and oil bonded. The type of sand casting process used is dependent upon production speed requirements, the size of the casting, environmental concerns and cost considerations.
Material:
Aluminum, Copper alloys, Gray Cast Iron, Nickel alloys, Steel, Magnesium alloys, Malleable Irons.
Pattern, Finish Allowance, and Wall Thickness
|
Metal |
Pattern Oversize Factor (each direction) |
Finish Allowance
(smaller number for larger sizes) |
Min Wall
mm
(inches) |
|
Aluminum |
1.08 - 1.12 |
0.5 to 1.0 % |
4.75 (0.187) |
|
Copper alloys |
1.05 - 1.06 |
0.5 to 1.0 % |
2.3 (0.094) |
|
Gray Cast Iron |
1.10 |
0.4 to 1.6 % |
3.0 (0.125) |
|
Nickel alloys |
1.05 |
0.5 to 1.0 % |
N/A |
|
Steel |
1.05 - 1.10 |
0.5 to 2 % |
5 (0.20) |
|
Magnesium alloys |
1.07 - 1.10 |
0.5 to 1.0 % |
4.0 (0.157) |
|
Malleable Irons |
1.06 - 1.19 |
0.6 to 1.6 % |
3.0 (0.125) |
Advantage
The number of cores can be reduced.
The gating can be made less elaborate.
The material wasted can be reduced.
The dimensional accuracy can be increased
Equipment
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