Question

Two identical cylindrical jobs are turned using $\left(a\right)$ a round nosed tool of nose radius $2mm$ and $\left(b\right)$ a sharp corner tool having principal cutting edge angle $={45}^o$ and auxiliary cutting edge angle $={10}^o$. If the operation is carried out of the feed of $0.08mm/rev,$ the height at micro irregularities on the machined surfaces (in $mm$) in the two cases will be

• A. $0.0001,0.024$
• B. $0.0002,0.012$
• C. $0.0003,0.024$
• D. $0.0004,0.012$

Answer 1

The correct option is D $0.0004,0.012$

$R_{f1}=\frac{f^2}{8r}=\frac{{0.08}^2}{8\times 2}=0.0004mm$
$R_{f2}=\frac{f}{tan\Psi +cot\gamma }$
$=\frac{0.08}{tan{45}^o+cot{10}^o}=0.012$