BIZOMAT MAKEOS · Manufacturing
Dividing-Head Setting for Fluting Angular Cutters and Taper Reamers
At what angle do I set the dividing head to flute the teeth of this angular cutter or taper reamer?
Dividing-head setting angle for cutting teeth in the conical face of an angular milling cutter or a taper reamer with a single-angle fluting cutter, from the number of teeth, the angle of the blank and the angle of the fluting cutter, including the case of a flat (0°) blank.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Number of teeth | Number of teeth to be cut. | |
| Angle of the blank | ° | Angle of the blank in which the teeth are cut (0 for a flat face). |
| Angle of the fluting cutter | ° | Angle of the single-angle fluting cutter. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Number of teeth
- What it is
- How many teeth are to be cut round the conical face of the angular cutter or taper reamer; it sets the index angle between teeth.
- Units and format
- Enter a plain number with no unit. The form accepts 5 to 200. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 9 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The index angle between teeth is 360° divided by this number.
What this means: Angle of the blank
- What it is
- The angle of the conical face of the blank in which the teeth are cut, as defined in the handbook construction for this setting.
- Units and format
- Enter a number in °: degrees of angle. The form accepts 0° to 85°. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 35° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Enter 0 for teeth cut in a flat face; angle D is then 90° and the simplified formula applies.
What this means: Angle of the fluting cutter
- What it is
- The angle of the single-angle milling cutter used to cut the flutes, from its marking or the cutter catalogue.
- Units and format
- Enter a number in °: degrees of angle. The form accepts 20° to 85°. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 55° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger cutter angle gives a larger dividing-head setting angle A.
Method and formulas
- tan D = cos(360° ÷ N) × cot B.
- sin E = tan(360° ÷ N) × cot C × sin D.
- Setting angle A = D − E; for a 0° blank this reduces to cos A = tan(360° ÷ N) × cot C.
- Handbook example: 9 teeth, 35° blank, 55° cutter → A = 21° 52′.
- Example: 9 teeth in a 35° blank with a 55° cutter need the head at 21° 52.2′.
Limitations
- Single-angle fluting cutters; check that the setting gives the land width wanted.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Set up to flute an angular cutter or countersink
- Cut teeth on a taper reamer blank
- Check a fluting set-up angle
Who it is for
- Toolmakers
- Machinists
- Cutter grinders
What you get
- Dividing-head setting angle A
- Intermediate angles D and E
- Index angle between teeth
Interpreting the result
- Take a trial cut and check the land width before fluting all teeth.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 833–834. Topic reference; no source tables or recommended settings are reproduced.
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Open the Dividing-Head Setting for Fluting Angular Cutters and Taper Reamers calculator