TAPPING SCREW Russian patent published in 2023 - IPC F16B25/00 

FIELD: fasteners.

SUBSTANCE: invention relates to a tapping screw. Tapping screw (10, 30) contains drive element (12) and thread-bearing rod (14) with main thread (16, 32). Main thread (16, 32) has maximum outer diameter (D_AF) of main thread, as well as it contains tapping part (F) and bearing part (T) following it in a direction of drive element (12). Rod (14), at end opposite to drive elements (12), contains screw end (18), diameter (D_E) of which is at least 20% of maximum outer diameter of main thread (D_AF). The rod, in the area of screw end (18), also contains inlet thread (20), while inlet thread (20) contains at least two strings (20a, 20b, 20c) of inlet thread, outer diameter (D_AA) of which does not exceed 90% of maximum outer diameter (D_AF) of main thread, and which form an inlet part, in which strings (20a, 20b, 20c) of inlet thread have a constant diameter profile, and, in addition, in inlet part (AB), a diameter of main thread (16, 32) is less than or equal to diameter (D_AA) of strings (20a, 20b, 20c) of inlet thread.

EFFECT: improvement of screwing characteristics.

17 cl, 6 dwg