Question

In ASA system, the side cutting and end cutting edge angles of a sharp turning tool are ${45}^o$ and ${10}^o$, respectively. The feed during cylindrical turining is $0.1mm/rev$. The centre line average surface roughness (in $mum$, round off to one decimal place) of the generated surface is______.

• A. 3.75

Answer 1

The correct option is A 3.75
Side cutting edge angle (SCEA) $={45}^o$
Ending cutting edge angle (ECEA) $={10}^o$
Feed $\left(f\right)=0.1mm/rev$
We have to consider nose radius is zero i.e.,
Ideal surface peak to valley surface roughness.
$h=\frac{f}{tanSCEA+cotECEA}$
The centre line average (CLA)
$=\frac{h}{4}=\frac{f}{4(tanSCEA+cotECEA)}$
$=\frac{0.1}{4(tan{45}^o+cot{10}^o)}mm=0.00375mm$
$=3.75mum$