Identical straight turning operation was carried out using two tools : $$8 - 8 - 5 - 5 - 5 - 25 - 0\,(ASA)$$ and $$8-8-5-5-7-30-0(ASA)$$. For same feed the tool which gives better surface finish is

Tool life testing on a lathe under dry cutting conditions gave $$'n'$$ and $$'C'$$ of Taylor tool life equation as $$0.12$$ and $$130$$ $$m/min,$$ respectively. When a coolant was used, $$'C'$$ increased by $$10\% $$. The increased tool life with the use of coolant at a cutting speed of $$90$$ $$m/min$$ is

For turning $$NiCr$$ alloy steel at cutting speeds of $$64m/min$$ and $$100m/min,$$ the respective tool lives are $$15min$$ and $$12$$ $$min.$$ The tool life for a cutting speed of $$144m/min$$ is

During orthogonal cutting of mild steel with a $$10$$ degrees rake angle tool the chip thickness ratio was obtained as $$0.4.$$ The shear angle (in degrees) evaluated from this data is