This machine adopts one straight needles,vertical-axis rotating hook with self-lubricating feature for catching thread loops and sliding bar take-up to produce two lines of double lockstitch.The needle bar can be engaged and disengaged mechanically and the arm shaft and hook shaft are suppported by ball bearings.It is provided with synchro tooth belt for driving,plunger pump for lubricating,knob-type stich regulator and lever type reverse feeding mechanism. It is recommended for stitching ouveralls, uniforms. jeans and decora-tive sewing on bags.