CNC Speeds and Feeds

Speeds and Feeds effect the tool life, finish of the machined surface, and power required of the machine. Utilizing the proper speeds and feeds in your shop, on your controls, can make a world of difference.

The cutting speed (sfpm) is mostly determined by the material to be cut and the material of the tool (carbide, HSS etc). To find the right speed for any task, refer to the Machinery's Handbook or your insert manufactures machining references.

The feed rate depends on the width and depth of cut, surface finish desired and many different variables. If your feed is too low, you'll get long stringy chips that won't break…. if your feed is too high you'll get thick chips resulting in chip crowding or crater wear. Ideally, you want to shoot for a self breaking chip or chips that look like 9's or 6's that are silver/blue in color.

Here is a sample chart for CNC turning: (NOTICE) These cutting speeds can be used to calculate spindle speeds however, such speeds are approximate and should be adjusted for type and condition of machine, exact dimensions of operation, and type of material being machined.

R = Rough F = Finish

Did you know?

An 80 degree insert is ideal for roughing, while a 55 degree is more suited for finishing.