In a sheet metal of $$2$$ $$mm$$ thickness a hole of $$10$$ $$mm$$ diameter needs to be punched. The yield strength in tension of the sheet material is $$100$$ $$MPa$$ and its ultimate shear strength is $$80$$ $$MPa.$$ The force required to punch the hole (in $$kN$$) is ______________

A rectangular hole of size $$100\,\,mm \times 50\,\,mm$$ is to be made on a $$5$$ $$mm$$ thick sheet of steel having ultimate tensile strength and shear strength of $$500$$ $$MPa$$ and $$300$$ $$MPa,$$ respectively. The hole is made by punching process. Neglecting the effect of clearance, the punching force (in $$kN$$) is

Calculate the punch size in $$mm,$$ for a circular blanking operation for which details are given below.

Size of the blank $$25$$ $$mm$$
Thickness of the sheet $$2$$ $$mm$$
Radial clearance between punch and die $$0.06$$ $$mm,$$ Die allowance $$0.05$$ $$mm$$

The shear strength of a sheet metal is $$300MPa.$$ The blanking force required to produce a blank of $$100$$ $$mm$$ diameter from a $$1.54$$ $$mm$$ thick sheet is close to