Balance screw of 5kw high frequency welding machine , used to adjust the welding board . The machine usage as bellow : PVC stationery industry :Gift bags welding , basketball embossing, albums making, cards inside pages welding,mouse pads welding, mirror box welding embossing,book cover sealing,ID card packing bag making,ID card cover sealing machinePU Leather industry ,PU and TPU leather ...