It is known that when bended on dies, sheet metals are prone to some amount of spring back depending on elastic deformation. Obtaining the size desired and design of die depends on the knowledge of the amount of this spring back. This research has been conducted to determine experimentally spring back of sheet metals on bending dies. The amount of spring back in sheet metals at different bending angles has been obtained by designing a modular "V" bending die. Furthermore, a contribution to the field literature is aimed through spring back graphics. Spring back graphics for three kinds of materials of different thickness have been obtained by using four different bending methods on eighteen different modular dies and a total of 720, 10 at least belonging to each of the kinds, copper sheet samples are bent. Spring back values are determined to be between 0,50 and 50. The effect of different bending methods to spring back effect and the applicability of the obtained graphics are also discussed. The results have shown that of the four different bending methods used in the field most, two cannot be employed for spring back effect, and that holding the punch longer on the material bent reduces spring back whereas an increase in the thickness of the material, and bending angle increase spring back values.