In rolling of a flat strip, the relative velocity of strip with respect to the roller is

The true stress at fracture of a tensile tested specimen, having an initial diameter of specimen at fracture is $$10$$ $$mm,$$ then the engineering stress, in $$MPa,$$ at fracture is ____________

In an open die forging, a circular disc is gradually compressed between two flat plates. The exponential decay of normal stress on the flat face of the disc, from the center of the disc towards its periphery, indicates that

A moving mandrel is used in