Question

Circular blanks of $35mm$ dia are punched from a steel sheet of $2mm$ thickness, If the clearance per side between the punch and die is to be kept as $40$ microns. The size of punch and die should respectively be

• A. $35$ and $835.040$
• B. $34.92$ and $35$
• C. $35$ and $35.080$
• D. $35.040$ and $34.92$

Answer 1

The correct option is B $34.92$ and $35$

Diameter of blank = Diameter of die
Diameter of die $=35mm$
Clearance $=0.04mm$ per side
Total clearance $=0.04\times 2=0.08mm$
Diameter of punch = Diameter of die - Clearance
$=35-0.08=34.92mm$