3 Fundamentals of press design

346 Sheet metal forming and blanking
holewithtapered
countersink
bevelledcut
weldedbuckle
one-sided
shearing
holewith
offsetting
roundededges semi-piercing
coining
cylindrical
countersink
cupdrawing
flanging
embossing
Fig. 4.7.14 Examples of different forming techniques which can be combined with
fine blanking
holewithcountersink
oneitherside
bending
Properties of the cut surface
The cut surface of fine blanked parts can be blanked smooth over the
entire workpiece thickness (100% of s). However, at times tearing and
fracture may occur. While tearing depends mainly on the microstructure
of the material (Fig. 4.7.10), fracture behavior is influenced by the
magnitude of the blanking clearance (Fig. 4.7.16).
For configuration of the dies and on-line in-process quality control,
the cut surfaces of a part must be described and defined in accordance
with the functional requirements.
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
Fig. 4.7.15
Fine blanked part featuring the
forming processes semi-piercing,
offsetting, cup drawing, coining,
bending, taper sinking and flanging