The literature data and the results of the authors’ studies on the effect of the fluctuations in the grade composition on the structure, phase composition, hardness, and machinability characteristics of the cutting of titanium alloys of Ti-Al-V and Ti-Al-Mo-V-Cr-Fe systems after different heat treatment are generalized. Ingots and deformed semi-finished products made of alloys VT6, VT22, VT23, VST2K for industrial production have been used as research objects. In order to assess the degree of alloying of various melts, equivalents have been determined for aluminum and molybdenum. Based on statistical analysis performed using the Stadia program, the range of values on the fact, the sample mean, the standard deviation, and the three-Sigma interval have been determined. The studied factors are: composition of alloying elements and impurities, aluminum and molybdenum equivalents, β-transus temperature, amount of β-phase, amount of primary α-phase, structural parameters ((-grain size, thickness and length of α - plates, α - colonies size), HRC hardness, machining characteristics during turning (cutting force, cutting area temperatures, tool life VK6OM) and during milling (cutting force, cutting area temperatures). In order to assess the strength of the relationship between the studied factors, a correlation analysis has been performed with a confidence probability of 0.95. It is shown that the vibrations of the grade composition and heat treatment modes can provide different levels of mechanical properties of alloys and machinability. Based on the conducted research, it has been found out that after annealing the cutability deteriorates with an increase in the composition of β-stabilizers, the amount of stable β - phase, and the hardness. An improvement in the machinability of alloys has been found out after quenching from critical temperatures, when the maximum amount of metastable β-phase is formed in the structure, which leads to a decrease in strength. After hardening and aging of VT6 and VT23 alloys, the main influence on the cutability is provided by the structural factor, especially the size of the β - grain. In the VT23 alloy, reducing the grain size by half (from 400 to 200 microns) leads to an increase the tool life of the VK6OM cutter by ~1.5 times.