The limits of cutting velocities (V) in a machine tool are decid­ed by the required minimum life of tool for maximum velocity (Vmax) and lower economically justifiable velocity for minimum velocity (Vmin). We have                       V=(ПdN/1000)m/min. where                                      d=dia in mm. N=R.P.M. For a constant value ...

Preferred numbers are nothing but a series of numbers in a geometric progression (G.P.), specially selected, to be used for standardization in preference to any other random number. It has been established statistically and by experience that dis­crete increment of a ...

In order to obtain a high surface finish the machine should be free from vibrations. Besides other factors, the design of the bed influences the vibration characteristics of the machine. Vibrations can be minimised by controlling the following factors with ...

To obtain an accurate feed motion proper levelling is impor­tant. The bed should be level in both longitudinal and transverse directions within the limits prescribed by relevant standards and it should be installed on firm foundation.

The main requirement of a lathe bed is to provide a guide for continued accurate longitudinal movement of the carriage and tailstock. This is a function of (1) Ability of the structure of the bed to resist distortion effectively due to ...