Determine the load required to punch a $$20$$ $$mm$$ diameter hole in $$2$$ $$mm$$ thick sheet. The properties of the material of the sheet are:
Tensile strength $$-580$$ $$MPa;$$
Yield strength in tension $$-410$$ $$MPa$$
Shear strength $$-350$$ $$MPa;$$
Yield strength in shear $$-250$$ $$MPa$$

The load in $$kN$$ is:

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