Title General geometric model for the cutting edge in thread turning
Authors Barz, Cristian ; Onysko, Oleh ; Kopei, Volodymyr ; Kusyi, Yaroslav ; Shkitsa, Lesia ; Dašić, Predrag ; Baskutis, Saulius
DOI 10.3390/machines14050549
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Is Part of Machines.. Basel : MDPI. 2026, vol. 14, iss. 5, art. no. 549, p. 1-37.. ISSN 2075-1702
Keywords [eng] trapezoidal thread ; flank angle ; rake angle ; inclination angle ; lead screw ; buttress thread ; deviation
Abstract [eng] Modern requirements for highly critical threads, such as drilling tool-joint threads or trapezoidal threads of heavy machine tools, impose requirements for high accuracy and at the same time wear resistance of thread cu􀁂ers. Conventional thread cu􀁂ers available on the global market have a profile that coincides with the thread profile. Their rake angle and the angle of inclination of the cu􀁂ing edge are typically zero. However, to ensure long tool life and high cu􀁂ing performance, such tools should have optimal values of the geometric parameters of the cu􀁂ing part, particularly the rake angle and the inclination angle of the cu􀁂ing edge. Non-zero values of these angles distort the thread profile, and there are currently no established algorithms for profiling such cu􀁂ers. This analytical study aims to develop an algorithm that enables the straightforward manufacture of high-performance and at high-precision thread cu􀁂ers with interpolated straight sides profile flanks for producing trapezoidal, triangular and bu􀁂ress threads, including those made of difficult-tomachine materials. The obtained analytical expressions accurately describe the cu􀁂ing edge of such cu􀁂ers as a hyperbola, functionally dependent on geometric parameters such as pitch, diameter and thread profile angle, as well as on the rake angle and the inclination angle of the cu􀁂ing edge. To simplify manufacturing, methods of rectilinear approximation of the curvilinear profile are proposed. The validity of such a replacement has been theoretically confirmed, as the maximum deviation of the hyperbolic profile from the linear approximation does not exceed 2 micrometers. The results indicate no significant deviations in the profile angle of the cu􀁂ers with relatively large rake and inclination angles (γ = 10° and λ = 7°). Deviations from the nominal profile angle of the trapezoidal thread profile angle of 15° do not exceed 0.1°, while for tool-joint threads (30°), they range from 0.01° to 0.09°. However, significant deviations in the profile (up to 0.49°) occur in the case of machining bu􀁂ress threads with a profile of 7°/45°. Experimental verification on a lathe confirms the theoretical results.
Published Basel : MDPI
Type Journal article
Language English
Publication date 2026
CC license CC license description