For the 7-type butt welding machine, you should connect the 6.5 and adjust the current to the maximum. Align the two ends and press them tightly. Make sure there is no dirt on the welding machine. Then turn on the power and squeeze the red part of the handle hard. Evenly, with extruded burrs, remove the burrs after a power outage and wait for cooling, then you can pull the wire through the mold. You control the current and adjust the filament current appropriately. The joints are not 100/100 and will be successful. qq number 994599484