This machine uses ultrasonic vibratory energy to intermix adjacent surfaces, creating frictional heat, melting and fusing similar thermoplastic materials. resin or filler may be necessary. the maching consists of power supply, horns, associated location and insertion devices and either magneto restrictive transducer or piezoelectric converter. in addition to welding, the process can be used to seal laminate, insert, stud weld and spot weld. frequencies used presently are from 20 to 40 kilohertz with amplitudes from .25 to 1.25 microns.