Question

A compound die is used to blank and punch a large washer out of 6061ST aluminum alloy sheet stock 3.2 mm thick. The outside diameter of the washer is 25.0 mm, and the inside diameter is 12.0 mm. Determine the punch and die sizes for (a) the blanking operation, and (b) the punching operation.

Answer 1

24.616 mm

12.384 mm

Step-by-step explanation:

`D_b` = Blanking die diameter = 25 mm

`D_h` = Punch diameter = 12 mm

a = Allowance = 0.06 for aluminium

t = Thickness = 3.2 mm

Clearance

`c=at\\\Rightarrow c=0.06* 3.2\\\Rightarrow c=0.192`

Diameter of punch is

`d_p=D_b-2c\\\Rightarrow d_p=25-2* 0.192\\\Rightarrow d_p=24.616\ mm`

Diameter of blanking punch is 24.616 m

For punching operation

`d_d=D_h+2c\\\Rightarrow d_d=12+2* 0.192\\\Rightarrow d_d=12.384\ mm`

The diameter of punching die is 12.384 mm