Shear - Principle of Sheet Metal Working

The cutting of strip material is termed as shearing. The principle of sheet metal working is displayed in Figures (a) and (b). The diameter of punch is smaller as compared to the diameter of die opening. Here, the material is subjected to both of the tensile and compressive stresses as displayed in Figures (a) and (b). At this point the stresses start to develop. If the clearance in between the die and punch is correct, the crack starting from the edges of punch and die meet, while the cracks do not meet up if the clearance is slightly more or less. Therefore, shearing action does not occur.