|
Casting
Processes - see Casting Definitions, General
Design Guidelines
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| Casting Process |
Advantages |
Disadvantages |
Recommended
Application |
| Sand
More Information:
Sand Cast Design
Guidelines
Casting Rib
Design
General
Design Guidelines
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-
Least Expensive in small
quantities (less than 100)
-
Ferrous and non- ferrous
metals may be cast
-
Possible to cast very
large parts.
-
Least expensive tooling
|
- Dimensional accuracy inferior to other
processes, requires larger tolerances
- Castings usually exceed calculated
weight
- Surface finish of ferrous castings usually
exceeds 125 RMS
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- Use when strength/weight ratio permits
- Tolerances, surface finish and low
machining cost does not warrant a more expensive process
|
|
Permanent and
Semi-permanent Mold
More Information:
Casting
Rib Design
General
Design Guidelines
|
- Less expensive than
Investment or Die Castings
- Dimensional Tolerances
closer than Sand Castings
- Castings are dense and
pressure tight
|
- Only non-ferrous metals
may be cast by this process
- Less competitive with
Sand Cast process when three or more sand cores are required
- Higher tooling cost than
Sand Cast
|
- Use when process recommended
for parts subjected to hydrostatic pressure
- Ideal for parts having
low profile, no cores and quantities in excess of 300
|
| Plaster
Cast
More Information:
Casting Rib
Design
General
Design Guidelines
|
- Smooth "As
Cast" finish (25 RMS)
- Closer dimensional
tolerance than Sand Cast
- Intricate shapes and
fine details including thinner "As Cast" walls are possible
- Large parts cost less to
cast than by Investment process
|
- More costly than Sand or
Permanent Mold-Casting
- Limited number of
sources
- Requires minimum of 1
deg. draft
|
Use
when parts require smooth "As Cast" surface finish and closer
tolerances than possible with Sand or Permanent Mold Processes |
| Investment
Cast
More Information:
Investment
Casting Using Stereolithgraphy
Casting Rib
Design
General
Design Guidelines
|
- Close dimensional
tolerance
- Complex shape, fine
detail, intricate core sections and thin walls are possible
- Ferrous and non-ferrous
metals may be cast
- "As-Cast" finish (64 - 125
RMS)
|
- Costs are higher than
Sand, Permanent Mold or Plaster process Castings
|
- Use when Complexity
precludes use of Sand or Permanent Mold Castings
- The process cost is
justified through savings in machining or brazing
- Weight savings justifies
increased cost
|
| Die
Cast
More Information:
Casting Rib
Design
General
Design Guidelines
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- Good dimensional
tolerances are possible
- Excellent
part-part dimensional consistency
- Parts require a minimal
post machining
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- Economical only in very
large quantities due to high tool cost
- Not recommended for
hydrostatic pressure applications
- For Castings where
penetrant (die) or radiographic inspection are not required.
- Difficult to guarantee
minimum mechanical properties
|
- Use when quantity of
parts justifies the high tooling cost
- Parts are not structural
and are subjected to hydrostatic pressure
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