Which code is used to specify a variable pitch in CNC programming?

The code used to specify a variable pitch in CNC programming is G96. This code is specifically utilized in turning operations to indicate constant surface speed (CSS) or variable pitch, where the spindle speed is adjusted based on the diameter of the workpiece being machined. By using G96, the CNC machine can maintain a consistent cutting speed throughout the operation, which enhances tool life and improves the finish of the machined surface.

Other codes mentioned do not relate to variable pitch: P.050 is not a standard G-code; G70 is typically used for finishing cycles in lathe programming; and G01 denotes linear interpolation, which is a movement command for a CNC machine but does not involve pitch control. Thus, G96 is the appropriate choice for specifying variable pitch in CNC programming.