Nutsert’s unique swaging action and the axial knurl under the flange are the secrets behind its superior holding strength. Nutserts are a one-piece design consisting of a nut portion and a sleeve portion. A rotating tool mandrel, which is inserted into the threads from the sleeve side, causes a separation at the grooved break area, drawing the “nut” portion into the sleeve. As the nut portion pulls-up inside the sleeve, the sleeve is expanded, exerting a powerful 360 degree swage fit against the parent material This expansion also causes the axial knurl, which is under the flange, to bite into the side of the hole, while the placing tool nose rolls the flange over, causing an additional locking against the top edge of the hole – a double-locking effect to insure superior torque-out resistance.