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Basic Information
Sheet metal forming is
a grouping of many complemetary
processes that are used to form sheet metal parts. One or more
of these processes is used to take a flat sheet of ductile metal,
and mechanically apply deformation forces that alter the shape of
the materia. Before deciding on the process(es), one should determine
whether a particular sheet metal can be formed into the desired
shape without failure.
Compared to casting and
forging, sheet-metal parts offer the advantages of light weight
and versatile shape.
| Process |
Characteristics |
| Roll
forming |
- long
parts with constant complex cross-sections;
- good
surface finish;
- high
production rates;
- high
tooling costs.
|
| Stretch
forming |
- large
parts with shallow contours;
- suitable
for low-quantity production;
- high
labor costs;
- tooling
and equipment costs.
|
| Drawing |
- shallow
or deep parts with relatively simple shapes;
- high
production rates;
- high
tooling and equipment costs.
|
| Stamping |
- includes
a variety of operations, such as punching, embossing, bending,
flanging, and coining;
- simple
or complex shapes formed at high production rates;
- tooling
and equipment costs can be high, but labor cost is low.
|
| Rubber
forming |
- drawing
and embossing of simple or complex shapes;
- sheet
surface protected by rubber membranes;
- flexibility
of operation;
- low
tooling costs.
|
| Spinning |
- small
or large axisymmetric parts;
- good
surface finish; low tooling costs, but labor costs can be
high unless operations are automated.
|
| Superplastic
forming |
- complex
shapes, fine detail and close tolerances;
- forming
times are long, hence production rates are low;
- parts
not suitable for high-temperature use.
|
| Peen
forming |
- shallow
contours on large sheets;
- flexibility
of operation;
- equipment
costs can be high;
- process
is also used for straightening parts.
|
| Explosive
forming |
- very
large sheets with relatively complex shapes, although usually
axisymmetric;
- low
tooling costs, but high labor cost;
- suitable
for low-quantity production;
- long
cycle times.
|
| Magnetic-pulse
forming |
- shallow
forming, bulging, and embossing operations on relatively
low-strength sheets;
- most
suitable for tubular shapes;
- high
production rates;
- requires
special tooling.
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Table adapted
from Kalpakjian, Manufacturing Engineering and Technology.
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