CNC cutting parameters determine how a cutting tool interacts with the workpiece during machining. The main parameters include cutting speed, feed rate, and depth of cut. Selecting suitable values can help improve tool life, machining efficiency, and surface quality.

Cutting Speed (Vc)

Cutting speed (Vc) is the speed at which the cutting edge moves relative to the workpiece. It is usually expressed in meters per minute (m/min). The appropriate cutting speed depends on the workpiece material, insert grade, cutting tool, and machining conditions.

Higher cutting speeds can improve machining efficiency, but they may also increase cutting temperature and tool wear. If the cutting speed is too high, insert life may decrease significantly. Always select a suitable cutting speed based on the insert manufacturer’s recommendations and the actual machining conditions.

Feed Rate (f)

Feed rate determines how far the cutting tool advances during each cutting cycle. In turning, feed is commonly expressed in millimeters per revolution (mm/rev). A higher feed rate can improve material removal efficiency, but excessive feed may increase cutting forces, surface roughness, and insert wear.

Excessive feed can overload the cutting edge and may cause chipping or premature tool failure. For finishing operations, a lower feed rate is often used to achieve a better surface finish. The appropriate feed should be selected according to the workpiece material, insert geometry, and machining operation.

Depth of Cut (ap)

Depth of cut (ap) refers to the thickness of material removed by the cutting tool in one pass. A larger depth of cut can increase material removal efficiency, especially during roughing. However, excessive depth of cut may increase cutting forces and affect tool stability.

Cutting speed, feed rate, and depth of cut work together to determine machining performance. The right combination depends on the workpiece material, insert grade, machining operation, and machine conditions. Adjusting one parameter may require changes to the others to maintain stable cutting and achieve the desired tool life and surface quality.

Start with the cutting parameters recommended by the insert manufacturer and adjust them according to the actual machining conditions. Consider the workpiece material, machining operation, machine rigidity, coolant, and required surface finish. Make small adjustments and monitor tool wear and cutting stability to find a suitable combination.

If you are unsure which cutting parameters to use, send us your workpiece material, machining operation, and current cutting conditions. We can help you review the requirements and identify a suitable starting point.