Machine Parts

The shaping operation may be performed in the same die as cutting operation, which deforms the mental to various degrees.   Shaping operations are generally divided into three groups: ·         Bending ·         Forming ·         Drawing       What is spring back? How does it can be prevented?    Spring back: Elastic stresses remaining in the bend area after bending pressure is released will cause a slight decrease in the bend angle. Metal movement of this type is known as spring back.      Prevention: it can be prevented in wiping dies by ‘ironing’ the material. To iron the bend effectively the distance between the punch & the die must be slightly less than the metal thickness. Ironing in the corner will be effectively accomplished only by using a slight shoulder on the punch that contacts the work material near the end of the stroke. The die may also be undercut to permit over bending when spring back is not too severe.  

Press tonnage:   Determine the die press tonnage for the given stock size of ½*2*2 inch made of cold rolled steel. Given that the shear strength of the material is 58 kg/inch. Press tonnage: The tonnage of a press is the force that the press ram is able to exert safely. What is the advantages of progressive die over compound die :   Progressive dies performs two or more operations at different stages every time the ram descends while a compound die performs two or more operations during one stroke of the press at one station only. But compound die is slower than progressive die. Moreover, progressive dies have advantages in case of long strip of material.