For tool $$A,$$ Taylor’s tool life exponent $$(n)$$ is $$0.45$$ and constant $$(K)$$ is $$90.$$ Similarly for tool $$B,$$ $$n=0.3$$ and $$K=60.$$ The cutting speed (in $$m/min$$) above which tool $$A$$ will have a higher tool life than tool $$B$$ is

In a machining experiment, tool life was found to vary with the cutting speed in the following manner

What is percentage increase in tool life when the cutting speed is halved.

In a machining experiment, tool life was found to vary with the cutting speed in the following manner

The exponent $$(n)$$ and constant $$(K)$$ of the Taylor's tool life equation are

Orthogonal turning is performed on a cylindrical work piece with shear strength of $$250Mpa.$$ The following conditions are used: cutting velocity is $$180m/min,$$ feed is $$0.2mm/rev,$$ depth of cut is $$3mm,$$ chip thickness ratio is $$0.5.$$ The orthogonal rake angle is $$7deg.$$ Apply Merchants theory for analysis,

The cutting and frictional forces respectively are