A low carbon steel bar of $$147$$ $$mm$$ diameter with length of $$630$$ $$mm$$ is being turned with uncoated carbide insert. The observed tool lives are $$24$$ and $$12$$ for cutting velocities of $$90$$ $$m/min$$ and $$120$$ $$m/min$$ respectively. The feed and depth of cut are $$0.2$$ $$mm/rev$$ and $$2$$ $$mm$$ respectively. Use the unmachined diameter to calculate the cutting velocity.

Neglect over travel or approach of the tool. When tool life is $$20min,$$ the machining time in $$min$$ for a single pass is

In orthogonal turning of low carbon steel pipe with principal cutting edge angle of $$90,$$ the main cutting force is $$1000$$$$N$$ and the feed force is $$800N.$$ The shear angle is $$25$$ and orthogonal rake angle is zero. Employing Merchants theory, the ratio of friction force to the normal force acting on the cutting tool is

In orthogonal turning of medium carbon steel, the specific machining energy is $$2$$ $$kJ/m{m^3},$$ the cutting velocity, feed and depth of cut are $$120m/min,$$ $$0.2mm/rev$$ and $$2mm$$ respectively. The main cutting force $$N$$ is

In an orthogonal machining operation:
$$\,\,\,\,\,\,\,\,\,\,$$Uncut thickness $$\,\,\,\,\,$$ $$= 0.5$$ $$mm$$
$$\,\,\,\,\,\,\,\,\,\,$$Cutting speed $$\,\,\,\,\,\,\,\,\,\,$$ $$= 20$$ $$m/min$$
$$\,\,\,\,\,\,\,\,\,\,$$Width of cut $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$= 5$$ $$mm$$
$$\,\,\,\,\,\,\,\,\,\,$$Chip thickness $$\,\,\,\,\,\,\,\,$$ $$= 0.7$$ $$mm$$
$$\,\,\,\,\,\,\,\,\,\,$$Thrust force$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$= 200$$ $$N$$
$$\,\,\,\,\,\,\,\,\,\,$$Cutting force $$\,\,\,\,\,\,\,\,\,\,\,\,$$ $$= 1200$$ $$N$$
$$\,\,\,\,\,\,\,\,\,\,$$Rake angle $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$ = {15^ \circ }$$
Assume Merchant’s theory

The values of shear angle and shear strain, respectively are