In a machining operation chip thickness ratio is $$0.3$$ and the back rake angle of the tool is $${10^ \circ }.$$ What is the value of the shear strain?

Two identical cylindrical jobs are turned using (a) a round nosed tool of nose radius $$2$$ $$mm$$ and (b) a sharp corner tool having principal cutting edge angle $$ = {45^ \circ }$$ and auxiliary cutting edge angle $$ = {10^ \circ }$$. If the operation is carried out at a feed of $$0.08$$ $$mm/rev,$$ the heights of micro irregularities on the machined surfaces (in $$mm$$) in the two cases will be

Consider the following statements with respect to the relief angle of cutting tool:

$$1.$$ This affects the direction of chip flow.
$$2.$$ This reduces excessive friction between the tool and work piece
$$3.$$ This affects tool life
$$4.$$ This allows better access of coolant to the tool-work piece interface

Which of the statements given above are correct?

In which of the choices given below, the cutting tool materials are placed in the ascending order of permissible cutting speed for machining of steel?