 | Cutting data
The following cutting data for milling cutters has been prepared in order to provide information on the best way to use our milling tools for milling of different materials under various operating conditions. These recommendations provide quick and simple guidelines for determining cutting speeds and feed rates for different applications with regard to cutting diameter, axial and radial cutting depths. The level of cutting data has been adapted to the performance of our milling cutters. A local adjustment to the speed and feed rates of individual machines is usually required.
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Conditions
- Milling tools of cobalt alloyed high speed steel according to our design.
- The cutting data information applies to end mills with short and normal cutting length respectively.
- A liberal supply of cutting liquid (emulsion) should be used.
- The information refers to rough milling and applies to end mills with plain cutting edges. Ra ~6 mm can be expected in end face and slot milling and Ra ~3 mm in plain milling.
- When machining low-carbon steels, the radial cutting depth should not exceed half of the mill diameter.
- For larger dimensions, the machine must have the capacity to hold the tool rigidly. For ³10mm end mills, holders for mills with flatted shank should be used.
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Data information are divided into six parts according to milling method
1. Slot milling with slot drill. This recommendation refers to two and three flute slot drills and to Minimills.
2. Slab milling with end mill. Maximum permissible radial cutting depth is 0.1 x cutter diameter.
3. Semi-finishing operation with end mill. Radial cutting depth = 0.25 x cutter diameter.
4. Roughing with end mill. Radial cutting depth = 0.8 x diameter.
5. End milling with shell end mill. Axial cutting depth = 0.05 x cutter height.
6. Slot milling with side and face milling cutter. Cutting depth = 0.1 x cutter diameter.
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Data sheet application
1. Select the correct group of material according to the list.
2. Select milling method.
3. Start from the relevant cutter diameter. (Use as large a cutting diameter as possible with regard to space available and type of machine.) Read recommended cutting speed for the relevant group of material.
Use the following formula for calculation of RPM:
| n = RPM |
| Vc = cutting speed m/min. |
| d = diameter in mm |
4. Select radial and axial cutting depth.
5. Read rate of feed/tooth (fz) for the milling method selected. Use the following formula for calculation of rate of feed/min.:
| Vf = rate of feed mm/min. |
| n = r/min |
| fz = rate of feed/tooth |
| Z = number of teeth on the cutter |
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Adaptation to the machine tool
Conventional milling machines usually have a limited number of selectable speeds and feed rates. The recommendations made must therefore be adapted to the values applicable to the machine being used. Adaptation should be done so that the recommended rate of feed per tooth is changed as little as possible. It is particularly important that the rate of feed per tooth does not increase for diameters < 10 mm.
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