Depth of cut (d) =2 mm Milling cutter diameter (D) =100mm over-travel distance is the same as the approach distance =√d(D−d)=√2(100−2)=14mm Total distance travelled by tool = length of sample + approach distance + overtravel =400+14+14=428 mm Feed per tooth = 0.05 mm No. of teeth =20 So, feed (f) =20×0.05=1 mm/rev Rotation speed (N) =1200rpm Therefore, machining time