Feed Feed is the r. RPM Revolutions Per Minute Spindle Speed Number of revolutions of spindle per minute. Speed is the rotational frequency of the tool Spindle Speed in revolutions per minute RPM.
Where d is the diameter of the work in inches and.
In the case of lathe machine cutting speed is the peripheral speed of the work past the cutting tool. It relates to spindle speed via variables such as cutter diameter for rotating cutters or workpiece diameter for lathe work. Again cutting speeds depend primarily on the kind of material you are cutting and the kind of cutting tool you are using. The hardness of the work material has a great deal to do with the recommended cutting speed.