Determination of spring-back of stainless steel sheet metal in “V” bending dies

Abstract

It is known that when bent 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, stainless steel sheet metal samples are bent. The results have shown that of the four different bending methods used in the field most, two cannot be employed for spring-back, 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. Spring-back values vary between 0.5° and 5°.