Question

The diameter of the smallest hole that can be punched in a 20 mm thick plate with ultimate shear strength of material is 152 MPa, and allowable crushing stress in the punch is 450 MPa is________.
(Correct upto two decimal place)

• A. 26.67

Answer 1

The correct option is A 26.67
$\frac{\pi }{4}{d}^2\times {\sigma }_c\ge \pi dt\tau d\ge 4t\frac{\tau }{{\sigma }_c}\ge 4\times 20\times \frac{150}{450}d\ge 26.67d=26.67mm$