The present paper reports the results obtained investigating surface work hardening in turning as a function of cutting speed, feed rate and tool wear. An experimental campaign was carried out using AISI 304 steel as workpiece material. Pipes 4 mm thick were machined under orthogonal cutting conditions. Tools with flat rake surface were adopted and dry cutting conditions were taken into account. Cutting speed and feed rate were varied and the tool wear was monitored using a CNC visiomeasuring machine. The tool wear was related to the workpiece strain hardening. Starting from micro Vickers test data, an analytical model representing the strain hardening behavior along a workpiece section was defined. In addition, a Fortran subroutine for the simulation of strain hardening by means of a 2D FEM code was implemented.