The tests reveal many results concerning springback. First of all,
we notice that the stretching height is the first factor of influence.
After measuring primary spring back Dh1, we notice that this latter
decreases rapidly with the increase of the stretching height for all
holding forces (see Fig. 5). This is due to the fact that the stretching
level is directly linked to the strain hardening of the sheet and to
the increase of plastic deformation in different zones. In the
absence of holding (tightening), the sheet slides easily between
the die and the blank holder. In this case, we have important