Cutting speed – vc (m/min)
This indicates the surface speed at diameter and forms a basic value for calculating cutting data.
Recommended cutting speeds for all materials and for different hex values are available in the Main catalogue.
Effective or true cutting speed
Indicates the surface speed at the effective diameter (Dcap).
This value is necessary for determining the true cutting data at the actual depth of cut (ap). This is a particularly important value when using round insert cutters, ball nose end mills and all cutters with larger corner radii, as well as cutters with an entering angle smaller than 90 degrees.
Spindle speed – n (rpm)
The number of revolutions the milling tool makes per minute on the spindle. This is a machine oriented value, which is calculated from the recommended cutting speed value for an operation.
Feed per tooth – fz (mm/tooth)
A basic value for calculating cutting data, such as table feed. It is also calculated with consideration of maximum chip thickness (hex) and entering angle.
Feed per revolution – fn (mm/rev)
Auxiliary value indicating how far the tool moves during one complete rotation.
It is used specifically for feed calculations and often to determine the finishing
capability of a cutter.
Feed per minute – vƒ (mm/min)
The table feed, machine feed or feed speed in mm/min it represents the movement of the tool in relation to the workpiece, dependent on feed per tooth (fz) and number of teeth in the cutter (zn).
Maximum chip thickness – hex (mm)
This value is a result of the cutter engagement as it is related to (fz), (ae) and (kr).
The chip thickness is an important consideration when deciding the feed per tooth, to ensure that the most productive table feed is employed.
Average chip thickness – hm (mm)
A useful value in determining the specific cutting force, used for net power calculations.
Metal removal rate – Q (cm³/min)
The volume of metal removed in cubic mm per minute. It is established using the values for cutting depth, width and feed.
Specific cutting force – kct (N/mm²)
A factor used for power calculations. The specific cutting force relates to the material resistance when cut at a specific chip thickness value.
Power Pc and efficiency ηmt
Machine tool oriented values, which assist in calculating the net power to ensure that the machine can handle the cutter and operation.
Machining time – Tc (min)
Machining length (lm) divided by the table feed (vf).