With a punch for which the maximum crushing stress is 4 times the maximum shearing stress of the plate, the biggest hole that can be punched in the plate would be of diameter equal to
- A. 1/4 x Thickness of plate
- B. 1/2 x Thickness of plate
- C. Plate thickness
- D. 2 x Plate thickness
Answer: C. Plate thickness
Explanation: Force to shear: $\pi d t \tau$. Force to crush punch: $\pi d²/4 \sigma_c$. Equating and using $\sigma_c = 4\tau$, we get $d = t$.