Calculate the Machining Time and the Material Removal Rate

A through hole of 40 mm diameter and 50 mm depth is to be drilled in a mild steel component. The cutting speed can be taken as 65 m/min and the feed rate as 0.25 mm/rev. calculate the machining time and the material removal rate.

Solution

Given  V = 65 m/min

f = 0.25 mm/rev

D = 40 mm

L = 50 mm

 Spindle speed

 N = (1000 × 65)/ (π× 40)

 = 527.35 rev/min

= 520 rev/min

Breakthrough distance

A =40 /2 tan 59^o

Total length of drill travel L = 50 + 12 + 3 = 65 mm

Time for drilling the hole = 65/ (0.25 × 520) = 0.50 minutes

The material removal rate = (π× 40² × 0.25 × 520) /4

= 163362.82 mm³/min

= 163.363 cm³/min.