Page 37 - Module DMV20173

3.0 SHEET METAL PROCESSES

e. Nibbling

1. In nibbling, a machine called a nibbler moves a small straight punch up and down
rapidly into a die.

2. A sheet is fed through the gap and many overlapping holes are made.
3. Using manual or automatic control, sheets can be cut along any desired path.

f. Scrap in shearing

1. Scrap can be a significant factor in manufacturing cost, and it can be reduced
substantially by efficient arrangement of the shapes on the sheet to be cut (nesting).
2. Computer-aided design techniques have been developed to minimize the scrap from
shearing operations.

3.2.3 TAILOR-WELDED BLANKS

1. An important variation from these conditions involves laser-beam butt welding of
two or more pieces of sheet metal with different shapes and thicknesses.
2. Because of the small thicknesses involved, the proper alignment of the sheets
prior to welding is important.

3. The welded assembly subsequently is formed into a final shape.
4. The result of this technique is
a. reduction in scrap;
b. elimination of the need for subsequent spot welding (i.e., in the making of the
car body);

c. better control of dimensions;
d. improved productivity.

BPLK 69 DMV 20173