Twisted files, pack of 3.

TF™ (Twisted File) is the first file to use a unique and patented production technology that achieves a combination of strength and flexibility.
R-Phase™ heat treatment technology optimizes the properties of NiTi files and provides 70% greater flexibility and 2-3 times higher resistance to cyclic fatigue compared to other rotary files.
By being drilled rather than ground, the surface structure of NiTi is optimized, which prevents the accumulation of microcracks. This process makes the file stronger; other endodontic files typically get their cutting edges by grinding or milling, which weakens the integrity of the metal and can lead to file breakage.
The advanced surface treatment of TF completes the surface treatment while preserving the grain structure of the metal. Tests have shown a higher strength in the files.