The influence of the value of the front angle and the angle of inclination of the cutting edge on the radial force when threading with taps

The purpose and normalization of the accuracy of the geometric parameters of the cutting part of the tool is directly related to the indicators of functional and parametric reliability of taps. The comparison of the taps test results showed that reducing the range of scatter of geometric parameters of the tool of the cutting part of taps makes the threading process more stable (leads to a significant reduction in the resistance dispersion, to a decrease in the number of breakdowns, and a decrease in the coefficients of variation of resistance and wear) and reduces the breakdown of the flank of the thread being cut. In this paper, the dependences of the change in the magnitude of the radial force on the elementary cutting profiles of the tap on the error of the spacing angle between the cutting teeth due to angular displacements of the main cutting blade owing to the presence of the front angle and the angle of inclination of the cutting edge are obtained. The obtained patterns of changes in the radial force on the cutting teeth of the tap can be used when considering alternative options for assigning the angle λ based on the criterion of minimum (limitation) of cutting forces during processing. A change in the front angle in the range of known recommended values does not significantly affect the nature of the change and the amount of radial force on the cutting teeth of the tap, as well as does not affect the one-sided direction of the radial force vector, characteristic of taps with a uniform spacing angle. The error of the spacing angle between the cutting teeth of the tap, due to the presence of the angle of inclination of the cutting edge λ, leads to an increase in the radial force and a change in the nature of the load on the cutting teeth of the tool. The obtained patterns of changes in the radial force on the cutting teeth of the tap can be used when considering alternative options for assigning the angle λ based on the criterion of minimum (limitation) of cutting forces during processing.