A hole of $$40$$ $$mm$$ diameter is pierced in a steel sheet of $$4$$ $$mm$$ thickness without shear on the tool. Shear strength of steel is $$400$$ $$N/m{m^2},$$ and penetration is $$25\% .$$ What is the expected percentage load reduction if a shear of $$1$$ $$mm$$ is provided on the punch?

In deep drawing of sheet metal, spring loaded stripper clamps the work until:

A hydraulic press is used to produce circular blanks of $$10$$ $$mm$$ diameter from a sheet of $$2$$ $$mm$$ thickness. If the shear strength of the sheet material is $$400$$ $$N/m{m^2},$$ the force required for producing a circular blank is

Consider the following statements related piercing and blanking
$$1.$$ Shear on the punch reduces the maximum cutting force
$$2.$$ Shear increases the capacity of the press needed
$$3.$$ Shear increases the life of the punch
$$4.$$ Total energy needed to make the cut remains unaltered due to provision of shear

Which of the above statements are correct