QuadCut External®

Cutting data

The table gives recommended cutting speeds in m/min. for different materials and carbide grades.

Number of passes

The table gives only general recommendations. Many times fewer passes can be used, depending on material and setup.

The above recommendations are for full profile UN, ISO and Withworth external forms. For Trapezoidal, ACME, NPT and internal profiles please contact your local QuadCut distributor.

Threading inserts

Toolholders

Cassettes

Helix angles

Over 90% of all common profiles have a helix angle between 0.5° and 2°. We have chosen 1.5° as the standard angle for QuadCut. In the diagram below the helix angle (λ) is shown as a function of the diameter (D2) and the thread pitch (P).

Other helix angles

When threading Trapezoidal and ACME profiles, or when producing a left hand thread with a right hand toolholder, cassettes other than the standard may be required. QuadCut cassettes are available in increments of 1,5° helix. The Internal Standard cassettes have 0.7° helix as standard.

Clearance angles

The side clearance angles on QuadCut are generated by tipping the External insert 10°, and the Internal insert 15° or 20°. Note that the clearance angle is larger for ISO Metric, UN and Whitworth profiles than it is for Trapezoidal and ACME. More care is required when selecting cassettes for Trapezoidal and ACME profiles, to ensure that the helix angle is as close as possible.

Inserts are available with three different coatings.

C-coating

The most universal coating is designated C and is an ordinary TiN coating that performs very well on most materials.

R-coating

Is TiAlN based and has been specially developed for threading operations. Excellent results have been achieved, particularly in stainless steels and other long chipmaterials. This is usually the universal problem solver.

L-coating

Shows good results in material such as G-X6CrNiMo1810 (CF8M). This coating can work up to 100°C higher temperature than our R-coating. It is the need to further boost productivity in processing and deploying a wide variety of challenging materials while improving process reliability even under the most difficult circumstances. The high aluminium content enhances oxidation resistance and hot hardness. The balanced coating hardness versus residual stress ratio opens up a broad spectrum of applications. High chemical stability optimizes crater wear resistance. Optimised thermal shock resistance makes L-coating ideal for wet and dry machining. Greater productivity thanks to higher cutting speeds and feed rates. Reliability and long tool service lives for maximized machine capacity utilization.

1. Choice of threading method

In this example the machine is rotating in a counter- clockwise direction with tools moving from right to left. This method will produce a right hand thread.

2. Choice of carbide grade

The most suitable grade for stainless steel is T10C, because of it ́s resistance to loose edge build-up. As this is an excellent all-round grade it will reduce your stock require- ments.

3. Choice of insert

Operation 1 See page 14. Choose 12E 2.0ISO T10C Operation 2 See page 17. Choose 12X 14W T10C Operation 3 See page 30. Choose 10N 14W T10R

4. Choice of helix angle

See the diagram on page 8. All threads lie within the field for helix angle 1.5°.

Op. 1 Cassette with helix angle1.5° should be used.

Op. 2 NOTE! Here a left-hand toolholder is used to make a right-hand thread. A cassette with negative helix angle must be used, i.e. 98.5.

Op. 3 Toolholder with helix angle 1.5° should be used.

5. Choice of toolholder and cassette

Op. 1 See page 23. The toolblock dimension is 25 mm. Choose cassette type toolholder QER 2525M-C25. For cassette see page 24. Holder shank is 25 mm, insert is 12E and helix angle 1.5°. Choose cassette QER 25-12.

Op. 2 See page 36. A left-hand blade cassette is chosen with negative helix to make a right-hand thread. A block for standard cut-off blade 32mm is available. Use QEL 3206D-12-98.5

Op. 3 See page 39
A right-hand tool holder with a small diameter and helix angle 1.5° is chosen. Use QNR 0010J-10-1.5

6. Choice of infeed method

See page 9. The material is long-chipping, and risk for cold hardening exists, so choice of correct infeed method is important. The machine is equipped with a G-function for alternating flank infeed, which should therefore be chosen.

7. Choice of number of passes

See the table on page 10. For the external threads use 7 passes and for the internal 10 passes, since the stability is lower. When programming the thread depth, see the respective page for the thread form being used.

8. Choice of cutting data

The table on page 10 shows that the carbide grade T10C can be run between 90–170 m/min in stainless steel.

\[ V_c = \frac{n \times \pi \times D}{1000} \]

\[ V_c = \text{surface speed in m/min} \]

\[ n = \text{spindle speed in rpm} \]

Op. 1 The lathe specifications show that n_max = 2200 rpm with pitch 2.0 and braking distance 2.5 mm.

\[ V_{\text{max}} = \frac{2200 \times \pi \times 42}{1000} = 290 \, \text{m/min} \quad \text{Choose 170 m/min} \]

Op. 2 The lathe specifications show that n_max = 950 rpm with pitch 14 TPI and starting distance 4.5 mm.

\[ V_{\text{max}} = \frac{950 \times \pi \times 24.2}{1000} = 72 \, \text{m/min} \quad \text{Choose 70 m/min} \]

The low surface speed can give a problem with loose-edge buildup.

Op. 3 There is no problem with start or braking distance, so maximum spindle speed can be utilized. The lathe specifications give n_max = 4400 rpm with pitch 14 TPI.

\[ V_{\text{max}} = \frac{4400 \times \pi \times 24.2}{1000} = 335 \, \text{m/min} \quad \text{Choose 180 m/min} \]