Compound Dies:

• In these dies, two or more operations may be performed at one station. Such dies are considered as cutting tools since, only cutting operations are carried out.
• Figure shows a simple compound die in which a washer is made by one stroke of the press.
• The washer is produced by simulation blanking and piercing operations.
• Compound dies are more accurate and economical in production as compared to single operation dies.

• Simultaneous blanking and piercing is achieved by providing blanking and piercing element in both the member of die, i.e. the upper and the lower member of the die.
• These elements are set exactly opposite to each other so that piercing punch acts in the opposite direction with respect to the blanking punch.
• In this way blanking and piercing operations are performed simultaneously.
• Angular clearance is provided in the piercing die.
• This helps in easy removal of scrap from the die. The blanking punch acts as a piercing die.
• The sidewall, which is adjacent to cutting edges of blanking die opening, is straight so that the blank does not pass through the die.
• Knock out stroke is actuated during the return stroke of the press. It ejects the blank.
• Compound dies are slow in operation but give close tolerance on workpiece.
• The flatness of the blank is achieved during cutting operation by knockout plate.
• Large parts can be blanked in a smaller press by using compound die.