7018 4mm electrode_how should we choose electrode sizes

We are professional factory of welding electrodes ( welding rods ), welding wire, welding blend powder and welding material, with powerful strengthen and advanced technology and the rights of self - supporting export . We introduced the international advanced level of electrodes production line and complete test equipment, our annual output is 50,000tons. The main products are mild steel ele - ctrodes, carbon dioxide welding wire , and many types of welding blend powder. With the arc stability , small spark , slag well -- distrib - uted cover, weld line moulding well, also have good metal strength , plastic nature , toughness, stomatal resistance ect specific character . Qur company registered trademark of COPPER BRIDGE , mainly sold to South America, Southeast Asi , England, Korea, America , Africa. All of products enjoy high prestige in the domestic and international market .