Abstract: An insert for plastic sections is manufactured from a flat strip of metal by high-speed progressive die-stamping which forms the strip into a threaded female insert. The metal strip is first cut into a flat blank and then thread regions are impressed on the face of the strip, providing a thread pitch profile. During the stamping operation, the strip is folded to form a triangular hollow tube with sharp-edged protrusions extending radially outward from each corner of the triangle. A tab and interlocking cutout secure the abuting longitudinal side edges of the strip and ensures axial alignment of the thread regions. As a result of the folding and stamping process, the thread regions lie along the interior wall of the tubular construction and define a thread pitch diameter which will accept the screw threaded into the center of the insert.