A 250 mm diameter part having a 100 mm diameter D2 hole is t

A 250 mm diameter part having a 100 mm diameter (D_2) hole is to be bored for 100 mm of its length to a diameter of 110 mm (D_1). A depth of cut of 2 mm (d) is to be used with a feed of 0.1 mm (f_f) and a cutting speed of 100 m/min. If it takes 15 seconds to return the tool to the starting point and set the depth of cut. Calculate the time required to complete this job. (No word limit, and you may handwrite your solution)

Solution

since depth of cut is 2 mm so in one pass 4 mm will be reduced.

no. of pass=(110-100)/4 =2.5

as number of passes should be a whole number not in decimals. so it hole of diameter 110 can\'t be made. instead can be made for 112 mm.