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:

In an interchangeable assembly, a shaft of $${20.00^{\matrix{ { - 0.015} \cr { - 0.005} \cr } }}\,\,mm$$ diameter and a hole of $${20.00^{\matrix{ { - 0.025} \cr { - 0.010} \cr } }}\,\,mm$$ diameter form a mating pair. In the worst assembly conditions, the clearance between them will be