Tool life equation for two tools under consideration are as follows

$$\eqalign{ & HSS:\,\,\,\,\,\,\,\,\,\,\,\,\,V{T^{0.2}} = 150 \cr & Carbide:\,\,\,\,\,\,V{T^{0.3}} = 250 \cr} $$
Where $$V$$ is the cutting speed in $$m/min$$ and $$T$$ is the tool life in $$min.$$ The breakdown cutting speed above which the carbide tool will be beneficial is

Orthogonal machining of a steel work-piece is done with a $$HSS$$ tool of zero rake angle. The ratio of the cutting force and the thrust force on the tool is $$1:0.372.$$ The length of cut chip is $$4.71$$ $$mm$$ while the uncut chip length is $$10$$ $$mm.$$ What are the shear plane angle $$\phi $$ and friction angle $$\beta $$ in deg.? Use Merchant's theory.

A single point cutting tool with a nose radius of $$0.4$$ $$mm$$ was used to turn a component in a lathe employing a feed rate of $$0.3$$ $$mm/rev.$$ If the feed-rate is doubled, the ideal surface roughness (peak-to-valley height) produced on the component will increase by a factor of

A cylinder of $$25mm$$ diameter and $$100mm$$ length is turned with a tool, for which the relation $$V{T^{0.25}} = 55$$ is applicable. The cutting velocity is $$22m/min.$$ For a tool feed of $$0.046$$ $$mm/rev,$$ the number of tool regrinds required to produce $$425$$ cylinders is