It was stated in Section 7.7.1 that the thicker the sheet metal, the higher is its curve in the

forming-limit diagram. Explain why. In forming-limit diagrams, increasing thickness

tends to raise the curves. This is because the material is capable of greater elongations since

there is more material to contribute to length.

2. Inspect the earing shown in Fig. 7.57, and estimate the direction in which the blank was cut.

The rolled sheet is stronger in the direction of rolling. Consequently, that direction resists

flow into the die cavity during deep drawing and the ear is at its highest position. In Fig. 7.57

on p. 394, the directions are at about ±45_ on the photograph.