*The stated cutting speeds are average values. In result of the milling process and the type of end mill adjustments might be necessary .Roughing: Reduction of up to 25 % – Finishing: Increase of up to 25 % – HSS end mill: Reduction of up to 50 % (hard materials) – VHM end mill: Increase of up to 25 %

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The cooling of non-ferrous metals occurs in best case with a lubrication system in combination with lubricant. Furthermore, the lubricating improves the surface quality and the service life of the tool. Lubricating with soap solution is suitable on acrylic glass. This improves an excellent surface.

The maximum possible infeed is usually reduced to the spiral length of the end mill, otherwise the shank will rub on the workpiece. Due to the relief-grinded shank, depths over several infeeds up to the maximum effective lengths are possible, thus, exceeding the spiral length.

Example calculation for aluminum (wrought alloy) with 8 mm end mill 2-flute:    n = 19904 rpm from upper formula    fz = 0,064 from chart    z = 2

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In downcut milling, the end mill pulls itself into the workpiece, which can lead to the gantry or the Z-axis beeing pulled uncontrolled (backlash of lead screw) in the direction of the workpiece during the removal of larger chips. This causes a less precise milling pattern and can even result in the breakage of the end mill, if the chip building is too large.Assuming backlash-free ball screws are used, the downcut is preferred over the upcut milling.

If the maximum speed of the milling motor is lower than the calculated value, the maximum speed of the milling motor needs to be inserted into the formula for the feed calculation.

During upcut milling, the end mill pushes away from the workpiece, which, when only removing little chips, quickly causes the cutting edge to push out of the workpiece. This leads to chatter marks which create an unclean surface and reduce the endurance of the end mill.The upcut milling is favored on machines with threaded lead screws which contain backlash.

Acrylic glass, wood, carbon or plastics – each material must be processed with a suitable end mill for the result to look as good as the idea. In addition, the speed and feed rate need to be adjusted accordingly. You will quickly gather your own empirical values, but there are also specific formulas for calculating the speed rate and other values. The easiest way is to use the free STEPCRAFT Milling Calculator. You can find it in the App Store and the Play Store. Simply select your machine, your material and your end mill and the STEPCRAFT Milling Calculator will show you the appropriate speed rate and cutting data in no time.

During contour milling, we recommend a lateral infeed of approx. 25 % of the end mill diameter while applying 100 % immersion depth.The immersion depth is conditional to the milling motor, the structure and the stability of the machine. This means a reduction of the values is required, when using a less powerful and / or lighter milling motor.

Suitability of lubrication system for cutting materialsCu AlloyAl Casting AlloySteel ferriticMg AlloyWrought Aluminum AlloyPearliticCast IronStainless Steels

To avoid increasing vibration of the end mill, we recommend clamping the bit as short as possible or as long as necessary.

Emuge Corp. has introduced Emuge-Franken, a line of solid-carbide end mills for universal milling, aerospace production, and high-hardness machining.

Keep up to date with the latest news, events, and technology for all things metal from our pair of monthly magazines written specifically for Canadian manufacturers!

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