1.Welding machine 2.Used for metal welding 3.High working rate 4.High quality parts 5. ... Convenient and save labour YP-D21 20Khz Ultrasonic Metal Welding Machine ... with the help of punch press ,forging machine or other equipments. 2.Smelting:Mainly aims ... hardware and tolls, automobile and motorcycle, machine tools, hardware parts and machine parts, hardware mold, etc.4. ...