Threaded insert having a small external diameter for screws having a trapezoidal thread

In a strong threaded insert of open or closed construction with symmetrical or asymmetrical trapezoidal external thread, on an external periphery thereof, and internal thread, on an internal periphery thereof, which insert has an axis and is secured via said external thread into a workpiece that has a corresponding female or internal thread, with said internal thread of said threaded insert being adapted to receive a high-strength screw that has a corresponding cooperating thread with a useful profile depth, the improvement wherein:

• said internal thread and said external thread of said threaded insert extend parallel to one another in such a way that said insert has repeated basic configurations formed in each case by a circumscribed quadrilateral;
• superimposed ones of said quadrilateral profiles are connected to one another by a web that has an axis which is parallel to said axis of said threaded insert, and that has a minimum wall thickness of about 30% of said useful depth of said screw thread, with said minimum wall thickness in any case being equal to at least 0.3 mm;
• and
• said external thread of said insert has an external diameter that is such that annular areas formed by projections of the used threaded flanks between the diameters of said external thread of said insert and said internal thread of said workpiece on said external periphery of said insert, and between the diameters of said screw thread and said internal thread of said insert on said internal periphery thereof, have equal areas.