Through hole tap – Aluminium and light alloys
Spiral point tap for through holes in aluminium and light alloys: the chip is pushed forward. Bright, 20 – 25° rake.
ISO N
Through holes
Bright
M2 – M36
Technical data sheet PDFCutting data, sizes and grades
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Description
Technical drawing
At a glance
| Hole type | Through holes |
| Geometry | Spiral point (gun nose) · 3 shallow straight flutes: strong core |
| Chamfer | Form B, 3.5 – 5 threads |
| Chip | Pushed forward, it exits from the bottom of the hole |
| Thread depth | Up to 3 × d (beyond: long version on request) |
| Rake angle | 20 – 25° |
| Tool material | HSS-E |
| Coating | bright (first choice) · alternatively CrN, DLC |
| Tolerance | 6H; 6G and 7G for threads to be galvanised or painted |
| Design | Reinforced shank from M2 to M10 (DIN 371), reduced shank from M12 (DIN 376); from M3 to M10 also with reduced shank for deep holes |
| Cutting direction | Right-hand; left-hand on request |
Workpiece materials
| Group | Aluminium and light alloysISO N |
| Strength | up to 600 N/mm² |
| Examples | EN AW-6082, 6061, 7075, 2011, 5083 and casting alloys with Si up to 10 % |
Sizes – ISO metric thread
| Thread | Pitch P | Tap drill Ø | L overall | l thread | Ø d2 shank | Square a |
|---|---|---|---|---|---|---|
| M2 | 0,4 | 1,6 | 45 | 8 | 2,8 | 2,1 |
| M2,5 | 0,45 | 2,05 | 50 | 9 | 2,8 | 2,1 |
| M3 | 0,5 | 2,5 | 56 | 11 | 3,5 | 2,7 |
| M3,5 | 0,6 | 2,9 | 56 | 12 | 4 | 3 |
| M4 | 0,7 | 3,3 | 63 | 13 | 4,5 | 3,4 |
| M5 | 0,8 | 4,2 | 70 | 16 | 6 | 4,9 |
| M6 | 1 | 5 | 80 | 19 | 6 | 4,9 |
| M8 | 1,25 | 6,8 | 90 | 22 | 8 | 6,2 |
| M10 | 1,5 | 8,5 | 100 | 24 | 10 | 8 |
| M12 | 1,75 | 10,2 | 110 | 28 | 9 | 7 |
| M14 | 2 | 12 | 110 | 30 | 11 | 9 |
| M16 | 2 | 14 | 110 | 32 | 12 | 9 |
| M18 | 2,5 | 15,5 | 125 | 34 | 14 | 11 |
| M20 | 2,5 | 17,5 | 140 | 34 | 16 | 12 |
| M22 | 2,5 | 19,5 | 140 | 34 | 18 | 14,5 |
| M24 | 3 | 21 | 160 | 38 | 18 | 14,5 |
| M27 | 3 | 24 | 160 | 38 | 20 | 16 |
| M30 | 3,5 | 26,5 | 180 | 45 | 22 | 18 |
| M33 | 3,5 | 29,5 | 180 | 50 | 25 | 20 |
| M36 | 4 | 32 | 200 | 56 | 28 | 22 |
Dimensions in mm. M39 to M100 and fine, pipe and inch threads on request. The tap drill Ø is the one recommended for tolerance 6H.
Coatings for aluminium and light alloys
| Coating | When to choose it |
|---|---|
| Bright (uncoated) ★ | The sharpest possible cutting edge: aluminium, copper and soft materials that do not tolerate rounded edges. |
| CrN – chromium nitride | Anti-sticking surface: aluminium, copper, brass and titanium, where the chip tends to weld onto the thread. |
| DLC – amorphous carbon (diamond-like) | Very low friction and no built-up edge: aluminium alloys, copper and engineering plastics in high-volume production. |
★ INNOT first choice for this material. Every tap can be supplied with any coating in the range: specify it in your request.
Starting data
| Cutting speed Vc | 15 – 30 m/min (lower value for uncoated substrate or machines with a compensating chuck) |
| Feed | Equal to the thread pitch: synchronised tapping or chuck with axial compensation |
| Lubrication | Plenty of emulsion or oil; never dry |
| Thread | Spindle speed (n) |
|---|---|
| M6 | 800 – 1.590 |
| M10 | 480 – 950 |
| M16 | 300 – 600 |
| M24 | 200 – 400 |
Guide values to be adapted to machine, clamping and lubrication. n = Vc × 1000 / (π × d).
Tips for use
- The chip exits ahead of the tap: leave free space under the part so it can fall without jamming.
- The long chamfer spreads the cut over more teeth and lasts longer: do not use this tap in blind holes.
- Avoid lean emulsions: aluminium welds onto the thread. With high-silicon alloys (over 10 %) use the cast iron tap.
- Chamfer the hole entry at 90°: clean start and no burr on the first thread.
Selection guide
Fine, pipe, inch and left-hand threads: special and custom threads.
Need a different tap?
Thread, tolerance, length, substrate and coating: tell us the material, hole type and depth and we will propose the right tap with a quote within 30 minutes.













