Calculate Machining Time and Material Removal Rate

A 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)

 = 517.25 rev./min

Breakthrough distance,

A =      40/2 tan 59 = 12.02 mm

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, MRR = (π× 40² × 0.25 × 520 )/4

= 163362.82 mm³/min

= 163.363 cm³/min