The following equation for tool life was obtained for H.S.S. tool VT0.13 f0.6 d0.3 = C. A 60 min tool life was obtained using the following cutting conditions.
V = 40 m/min, f = 0.25 mm, d = 2.0 mm. Calculate the effect on tool life if speed, feed and depth of cut are together increased by 25% and also if they are increased individually by 25%; where f = feed, d = depth of cut; V = speed.