NiTi Alloy

# R-Phase NiTi (Twisted)

R-phase NiTi utilizes a thermomechanical twisting process to manufacture files, resulting in a wire with a unique R-phase crystalline structure alongside austenite. The twisted manufacturing method creates compressive surface residual stresses that substantially improve cyclic fatigue resistance compared to conventional ground files. R-phase NiTi has a lower elastic modulus than austenitic NiTi, providing excellent conformability in curved canals. When used in the TF Adaptive system with adaptive motion technology, the stress-sensing motor switches automatically between rotation and reciprocation based on real-time torque feedback, maximizing both efficiency and safety.

## Metallurgical Properties

Af Temperature~25–35°C

Phase at 37°CAustenite + R-phase

FlexibilityHigh (twisted fiber structure)

Cyclic FatigueSubstantially improved vs ground files

[Compare all heat treatments→](https://endo-guide.app/alloy/heat-treatment-comparison)

## Systems Using R-Phase NiTi (Twisted)

[### TF Adaptive Kerr Dental Adaptive R-Phase · 4-8% · 6 files Rotary When You Want It, Reciprocation When You Need It](https://endo-guide.app/system/tf-adaptive)[### K3XF Kerr Endodontics Rotary R-Phase™ · 4-10% · 24 files R-Phase Enhanced K3 Design](https://endo-guide.app/system/k3xf)

## Related Clinical Links

NiTi collections

[Rotary Systems](https://endo-guide.app/niti-files/rotary-file-systems)[Single-Use Systems](https://endo-guide.app/niti-files/single-use-niti-files)

Clinical use cases

[Severe Curvature](https://endo-guide.app/use-case/severe-curvature)[Calcified Canals](https://endo-guide.app/use-case/calcified-canals)

Related alloys

[Gold Heat Treatment](https://endo-guide.app/alloy/gold)[Blue Heat Treatment](https://endo-guide.app/alloy/blue)[CM-Wire (Controlled Memory)](https://endo-guide.app/alloy/cm-wire)[C.Wire (Controlled Memory)](https://endo-guide.app/alloy/c-wire)

![Uzm. Dt. Levent Yüksel](https://endo-guide.app/images/levent-yuksel.jpg)

Reviewed by

Uzm. Dt. Levent Yüksel

DDS · Endodontist

Endodontist — DDS, Hacettepe University; endodontics specialty training, Ankara University. 10+ years of clinical experience. Sole author and reviewer of EndoGuide content.

[About the author](https://endo-guide.app/about)[Editorial policy](https://endo-guide.app/editorial-policy)[Clinical profile](https://drleventyuksel.com/)

[Back to all systems](https://endo-guide.app/)

---

Canonical HTML: https://endo-guide.app/alloy/r-phase · Agent guide: https://endo-guide.app/llms.txt