Free-cutting steels are non-alloyed steels with a high content of sulfur (S) and manganese (Mn). Thanks to the manganese and sulfur, these steels allow for faster production due to the formation of small and brittle chips during machining. Due to their easy machinability, they are defined as the most suitable steels for longitudinal and face turning, threading, drilling, reaming, and other chip removal processes performed on single or multi-spindle automatic lathes, turret lathes, and similar machines.
By adding lead (Pb) to these steels, cutting speeds can be increased. Free-cutting steels are classified into three groups: those subjected to heat treatment, those not subjected to heat treatment, and those subjected to carburizing.
Free-cutting steels are used cold-drawn with precise dimensional tolerances. They are produced with surface precision within h9 and h11 tolerances.
