Machine Parts

  Condition of a shallow drawing operation :   “The cup is no deeper than half its diameter” is the condition of a shallow drawing operation. Double action draw die:   When the die is designed for a double action press with the blank holder fastened to the outer ram, which descends first and grip the blank then the die is known as double action draw die. The punch is fastened to the inner ram, which descends next to form the part.  The cup may be pushed through the die or ejected back through the die by use of a knockout actuated by an air cushion. The knockout may also be used to hold the blank firmly against the punch nose during the punch operation.

Progressive die : The dies which performed two or more operations at different stages every time the ram descends is known as Progressive die.   The principle advantage of Progressive die is in the number of operations that can be achieved with one handling of the stock strip. The main disadvantage is that work pieces may become “dished” as they pushed through the die as they generally have very little support. Compound die : A compound die differs from a progressive die in that it performs two or more cutting operations during one stroke of the press at one station only.   Compound dies are slower in operation than progressive dies but they have advantages for certain jobs, especially where tolerance are close (1) the cutting operation, by the action of the knockout plate ,ensures flatness of the blank.2 Large parts can be blanked in a smaller press if compound dies rather than progressive dies are   used. Combination dies:   A die in which a cuttin