Inserting
A process of securing an insert to a plastic part. The insert diameter is slightly larger than the hole in the plastic part. As the insert is pushed into the hole by the horn, the ultrasonic vibration causes the plastic to melt and flow around the ridges or knurls on the outside of the insert. When the plastic solidifies, a mechanical joint forms between the plastic and the insert. When properly performed, this joint has low residual stress.