Blanking and Punching size:A compound die will be used to blank and punch a large washer out of 6061ST aluminum alloy sheet stock 3.80 mm thick. The outside diameter of the washer is 60.0 mm and the inside diameter is 28.0 mm. Determine (a) the punch and die sizes for the blanking operation, and (b) the punch and die sizes for the punching operation.

punch and die sizes for the blanking operation = 59.54 mm

punch and die sizes for the punching operation = 28.456 mm

Explanation:

Given dа ta:

aluminum alloy sheet thickness = 3.80 mm

outside diameter of the washer = 60.0 mm

inside diameter = 28.0 mm

the allowance is a = 0.06

To find:

punch and die sizes for the blanking operation = ?

punch and die sizes for the punching operation = ?

Calculation:

Since a = 0.06, the clearance is given by,

c = 0.06 (3.8) = 0.228 mm

(a) Blanking punch diameter = Db = 60 mm

= D (b) - 2c

= 60 - 2 (0.228)

= 60 - 0.456

= 59.54 mm

(b) Punching punch diameter = D (h) = 15 mm

= Dh + 2c

= 28 + 2 (0.228)

= 28 + 0.456

=28.456 mm