In a band brake the ratio of tight side band tension to the tension on the slack side is $$3.$$ If the angle of overlap of band on the drum is $${180^ \circ }$$ the coefficient of friction required between drum and the band is

Hardness of green sand mould increase with

With a solidification factor of $$0.97 \times {10^6}s/{m^2},$$ the solidification time (in seconds) for a spherical casting of $$200$$ $$mm$$ diameter is

Cold working of steel is defined as working