For a given milling operation, it was decided to switch from HSS cutter $($cutting speed $35\frac{m}{m}in)$ to carbide cutter $($cutting speed $110\frac{m}{m}in).$ The other parameters of the cutting operation in the two cases are:

$\backslash$table$[[,$Carbide cutter,HSS cutter$],[$Cutter diameter $(mm),150,125],[$Feed tooth$),0\mathrm{.}055,0\mathrm{.}0425],[$Number of teeth,$15,10]]$

Calculate the following for each of the cutting tool

$($a$)$ Cutter rpm

$($b$)$ Feed in $m\frac{m}{m}in$

$($c$)$ Time required to take $200mm$ long cut including approach and overtravel

$($d$)$ Percentage saving in time by changing from HSS to carbide tool