CLASSIFICATION OF FORMING PROCESS
The sheet metal forming processes can be classified into mainly two categories. They are:
Shearing Process
Shearing is a cutting operation used to remove a blank of required diemnsions from a large
sheet. Shearing process includes.
Punching
Blanking
Perforating
Parting
Notching
Lancing
Principle of Shearing
When a punch penetrates a sheet metal workpiece and enters in to the die, a section through the
work piece provides a smooth cut area
Punching
In punching, hole is the discarded product, the material punched out to form the hole being
waste. i.e., the cut out part is waste and left out piece is of importance
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| Punching |
Blanking
If the removed piece is the useful part and the rest is scrap, the operation is called blanking. The
cut out part from the strip is the required component.
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| Blanking |
The main difference between the punching and blanking is that in punching the metal inside the
part is removed and in blanking the metal around the part is removed.
Perforating
Punching a number of uniformly spaced holes in a sheet is called perforating. The holes may be
of any size and shape
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| Perforating |
Parting
Shearing the sheet into two or more pieces is called parting. It is shown in Fig.
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| Parting |
Notching
Removing pieces from the edges is called notching. It is an operation in which a specified small
amount of metal is cut from a blank.
