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| 1. |
Choice
of Alloy selection : Practically any alloy
can be investment cast wide range of ferrous alloys
are regularly cast at Thirumala Precicasts Pvt. Ltd.
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| 2. |
Design
Flexibility : Almost any shape or complex can be
investment cast. Investment casting offers designers
freedom of design in wide range of alloys with close
dimension tolerances and fine details. |
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3.
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Cost
Reduction : Investment casting offers a near net shape
then reducing or eliminating costly machining operations. |
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| 4. |
Increase
manufacturing Capacity : As almost final shape is
available on investment casting, machine tools are released
for finish machining operations.
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| 5. |
Cut
Assembly Operations : Complex assemblies can be
cast as per single unit reducing handling, assembly
and inspection cost.
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| 6. |
Casting
Capability : Casting weight from 2 gms to 10 kg
can be cost at TPPL. Max. casting size 14" x 16".
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| 8. |
Flatness
:
Flatness refers to single plane surface and is usually
a function of volumetric shrinkage.
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METRIC
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Thickness
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Dish
per 42 sq. cm of surface
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| Up
to 6.5 mm |
Insignificant |
| 6.5
mm to 13 mm |
0.102
mm TIR |
| 13
mm to 25 mm |
0.201
mm TIR |
| 25
mm to 50 mm |
0.406
mm TIR |
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| 9. |
Straightness
:
Tolerances
for axial straightness : .005
in per inch (.127
mm per 25 mm) as cast.
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| 10. |
Concentricity
:
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| a. |
Concentricity
of diameters in a shaft is also a function of
straightness. Centers will be concentric within
.005 in per inch (.127
mm per 25 mm) of maximum separation.
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| b. |
Centers
of I.D. to O.D. will be concentric within .003
in per 1/2 in. (.076 mm per 13 mm) of wall thickness.
This disregards out-of-roundness, and assumes
measurements in the same plane if the concentricity
is being measured in separate planes, the requirements
of paragraph 1 above must be added.
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| 11. |
Angles
:
As-cast
tolerances of angles depend on their location in casting.
They range from 1/2
degree for well supported positions to 2
degree where inherent distortion could be expected.
Inclusion of gussets and ribs often minimizes distortion
and many sections can be mechanically straightened.
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SURFACE
FINISH
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Metal
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MICROMETERS
AverageRa
Value
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| Aluminium |
1.50
- 2.50
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| Beryllium
Copper |
1.50
- 2.50
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| Cobalt
Chrome |
2.00
- 2.50
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| 300
Series Stainless |
2.25
- 3.20
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| Carbon
Steel |
2.25
- 3.20
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| 400
Series Stainless |
2.50
- 3.20
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