The main cutting force acting on a tool during the turning (orthogonal cutting) operation of a metal is $$400N.$$ The turning was performed using $$2mm$$ depth of cut and $$0.1mm/rev$$ feed rate. The specific cutting pressure (in $$N/m{m^2}$$ is

Friction at the tool - chip interface can be reduced by

The minimum shear strain in orthogonal turning with a cutting tool of zero rake angle is

Formation on build-up edge during machining can be avoided by using