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The whirling process How to thread tough and difficult materials

used for aeronautic parts

Mr. Rolf Herg ert

DIXI Polytool- GmbH

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Inconel 718

Inconel 625

NimonicStellite

Titaniums

A lot o f componen ts a re made o f super al l oys- t he m ost di f f ic ul t and c ost ly m at er ia ls t o be m ac hined

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TapsThread mill Spcial thread mill

- whirling tool -

Di fferen t techn iques for i n te rna l th reading

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1corrector

2corrector

Classical Thread Mills

Why w h ir l ing too ls a re more e f fi c ient t han t h read mi l ls

With traditionel thread mills thecomplete length of the cutting edge is inthe material during the work process.

As super alloys are extremly tough andabrasive the threading operation hastherefore to be done in several stepsand corrections.

Cutting edge

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Whirling tools DIXI 1730

Why w h ir l ing too ls a re more e f fi c ient t han t h read mi l ls

Cutting edge

With wirling tools the length of the cuttingedge which is in the material duringoperation is substantially shorter.

As a result the lateral forces on the tool arelower.

This is the reason why the thread can be

made in one infeed.

It is also possible to use these tools in up milling

down milling

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DIXI 1730 Too l cha rac te r is t i cs

Reinforced shank

Neck

Short cutting lengthwith 2 profiles

2 profiles with Z3 or Z6 according to thediameter

2 times nominal

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DIXI 1730 Pr inc ip le Up m i l l ing

-1-

Move to startingposition. The X-

position correspondsto the final threaddiameter(corrector

hold)

The tool rotates.

-2-

Machining with a toolpath a spiral down to

the bottom of thethread.

-The thread is machinedpitch per pitch.

-3

End of the thread

-4

Move towards thecentre (corrector

cancellation)

-5-

Move of the tool outof the workpiece.

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with 2 profiles Z=3

Tools m ac hin ing m et hod

The core hole drill sizes are carried out to the minimal tolerance. The tool cuts

the complete profile of the thread.

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M 5 x 0.8010 mm

Stainless steelX4CrNiMo16 5 1, 1300 MPa

DIXI 1730 SP TiAlN3.90 mm50 m/min.5000 rpm.0.015 mm/tooth225 mm/min600 threads M5

With a special DIXI 1730 TiAlN coated whirling tool, tool life is 25 workpieces: 600 threadswith one infeed.The tool life with a standard thread mill used to be 20 threads (with 3 infeeds).

Thread milling :Depth :

Material :

Whirling tool ::

Vc :n :fz

Vf :Number of threads /:

Mach ining examp les

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M 4 x 0.70

8 mmNimonic (nickel alloy)

DIXI 1730 standard (Z=4)3.20 mm50 m/min.

5000 rpm.0.007 mm/tooth140 mm/min100 threads M4

Thread milling :

Depth :Material :

Whirling tool ::

Vc :

n :fzVf :

Number of threads :

Mach ining examp les

In this case we had to machine 50 threads M4 in Nimonic. This was not feasible with a tap.

Result : we obtained 100 threads without any problem.

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10 32 UNF EG 8 mm

8.20Inconel 718

DIXI 1730 4.50 x 1.587 x6 x 57 Z=34.50 mm

30 m/min.2200 rpm.0.015 mm/tooth100 mm/min50 threads

Thread milling :

Depth :Material :

Whirling tool :

:

Vc :n :fz

Vf :Number of threads :

Mach ining examp les

The objective was to obtain the highest quantity of holes.

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Thread milling :Depth :

Material :

Whirling tool : :

Vc :n :fz :Vf :

Number of threads :

M 8 x 1.2518 mm

Staballoy AG17 (Heat resisting stainlesssteel - 17% Cr, 18% Mn, 32 HRC)

DIXI 1730 M8 x 1.25 without coating6.5 mm15 m/min.734 rpm.0.03 mm/tooth132 mm/min1 Threads up milling / 70 Thread down milling

A primary test has been made by the customer. The objective was to machine a thread in less than 3minutes and to prove that a DIXI 1730 could be used in that kind of material. Moreover, the test revealedthat working as down milling in that material gives much better results than as up milling.

Mach ining examp les

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Thread milling :

Depth :Material :

Whirling tool ::

Vc :

n :fz

Vf :Number of threads :

M 4 x 0.70

6 mmTool steel 1.2344 - 56HRC

DIXI 1730 M4 x 0.703.20 mm23 m/min.

2250 rpm.0.0035 mm/dent23 mm/min55 Threads down milling / 65 Threads up milling

For this customer we proved that it is possible to machine such toughmaterial with this threading method.

Mach ining examp les

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So me o bs er va t io ns Wh ir li ng to ol s DIXI 1 7 30

1- These tools are an excellent alternative to conventional thread mills or taps for internal threading. They

are especially suitable for very tough materials as titaniums, heat resisting stainless steels, special alloys(Nimonic, Inconel).

2 - These tools, with a longer neck, are efficient for relatively deep threads (around 2 to 4 times to thread)

3 - Less problems with chips (short chips). It is not necessary to stop the machining process for chip

evacuation. In terms of productivity, the thread whirling process is more profitable than the tapping process.

4 - Higher precision in comparison to traditional tapping process. The thread is straight and tends muchless to be conical. Further it is possible to adjust the nominal diameter according to the required tolerances(6H, 5H).

5 As it is a milling process excellent surface finish can be obtained. It is possible to produce without burrs

6 -The thread can be machined very close to the bottom of blind holes.

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DIX I 1730 M0.80 M10 ISO 60 (2xnom.)

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DIX I 1731 M0.80 M10 ISO 60 (3xnom.)

3 x nominal diameter

3 x le nominal

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DIXI 1735 UN 60 (2xnom.)

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DIXI 1736 UN 60 (3xnom.)

3 x nominal diameter

3 x le nominal

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DIXI 1739 S0.30 S1.40 se lon norme NIHS 06

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Whir l ing t ools DIXI 1730

On request we can manufacture whirling toolsaccording to any special profiles.

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