Fluteless machine taps
Tools for chipless thread forming
Fluteless taps (also known as forming taps or roll taps) are threading tools for the chipless production of internal threads. The thread is formed by deformation and work hardening without chip removal, whereby the material's fibre structure is preserved.
Advantages of fluteless machine taps:
- Longer service life than cutting taps
- Uniform dimensional and profile accuracy
- Higher permissible operating speed
- Higher load capacity of the formed threads
- No chip formation = no chip removal
⚠️ The core hole diameters for thread forming differ from those for thread cutting. The table below shows the recommended core hole diameters. You can also find further information and application recommendations here.
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Recommended application for fluteless machine taps
Suitable materials for the use of fluteless taps are, in particular, all cold-formable materials with good elongation at break and flow properties. These include aluminium or non-ferrous metals such as copper, brass or bronze.
Fluteless taps, bright
Particularly suitable for long-chipping brass, bronze, and aluminium as well as copper and zinc alloys.
Fluteless taps, steam tempered
Particularly suitable for stainless steels and constructional steel with a tensile strength of up to approx. 700 N/mm².
Fluteless taps with TiN coating
Particularly suitable for unalloyed and low-alloy steels, heat-resistant steels and constructional steel with a tensile strength of up to approx. 900 N/mm².
⚠️ Fluteless taps with oil grooves
For thread depths greater than 1.5xD, fluteless taps with oil grooves should always be used. Graphite-containing, high-lubricity cooling lubricants or thread cutting oils are particularly suitable for thread forming.
Fluteless taps with oversize
If the workpieces are to receive a galvanic protective coating afterwards, the use of fluteless taps with tolerance class ISO3 (6G) with the corresponding oversize is recommended. After applying the galvanic protective coating with a layer thickness of 0.02 - 0.04 mm, a dimensionally accurate thread is retained despite the coating.
Recommended core hole diameters (tap drill sizes) for thread forming of metric coarse threads
| M 1 | M 1.1 | M 1.2 | M 1.4 | M 1.6 | M 1.7 | M 1.8 | M 2 | M 2.5 | M 3 | M 4 | M 5 | M 6 | M 8 | M 10 | M 12 | M 14 | M 16 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.90 mm | 1.00 mm | 1.10 mm | 1.25 mm | 1.45 mm | 1.55 mm | 1.65 mm | 1.80 mm | 2.30 mm | 2.80 mm | 3.70 mm | 4.65 mm | 5.55 mm | 7.45 mm | 9.30 mm | 11.20 mm | 13.00 mm | 15.10 mm |