A parting tool has a ground front clearance angle of $${6^0}$$ and the back rake angle of $${10^0}$$. The tool, by mistake, was set $$1.5$$ $$mm$$ above the line of centers while machining a job of $$50$$ $$mm$$ out-side diameter.

The effective rake and clearance angle are

In comparison to $$HSS$$, super $$HSS$$ contains higher percentage of

$$BUE$$ formation ......A... the cutting force and ......B...... the surface finish

(a) decreases/ increases
(b) spoils / improves

Calculate the smallest punch diameter that can be designed for piercing sheet metal strip with the following data. Crushing strength of the punch material is $$1500$$ $$MPa.$$ Thickness of the sheet is $$2$$ $$mm,$$ factor of safety is $$3,$$ and shear strength of the sheet material $$500$$ $$MPa$$ is