Page 51 - Module DMV20173
P. 51
3.0 SHEET METAL PROCESSES
Figure 3.22 The methods of bending tubes.
Figure 3.23 (a) The bulging of a tubular part with a flexible plug. (b) Production of
fittings for plumbing by expanding tubular blanks under internal pressure.
3.3.4 DIMPLING, PIERCING AND FLARING
1. In dimpling, a hole first is punched and then expanded into a flange.
2. Flanges also may be produced by piercing with a shaped punch.
3. As the ratio of flange diameter to hole diameter increases, the strains
increase proportionately.
4. Depending on the roughness of the edge, there will be a tendency for
cracking along the outer periphery of the flange.
BPLK 83 DMV 20173
