Z308 is a welding pure nickel core, strong reduction of the iron coating graphite electrode type, welding, the weld pieces from time to preheat, good crack resistance and processability. Nickel is expensive, should be satisfied in other rods can not be selected. AC and DC. Uses: used thin pieces of cast iron welding and machining surfaces, such as engine blocks, machine guides, gear housing and other important gray cast iron. Z408 is a nickel-iron alloy solder core, strong reduction of the iron coating of graphite electrodes, high strength, good plasticity, low coefficient of linear expansion. Crack resistance of gray cast iron and the Z308 is almost, but cast iron is stronger than the Z308, and high phosphorus content (0.2% P) of cast iron, also has good results, cutting slightly worse performance than the Z308 and Z508. For room temperature or slightly preheated (to about 200 ℃) gray iron and ductile iron welding. AC and DC. Uses: Suitable for important high-strength gray cast and ductile castings welding. Such as cylinder, engine blocks, gears, rollers and so on. Z508 is a nickel-copper alloy (Monel) welding core, strong reduction of graphite cast iron welding rod coating. Its process performance and cutting performance are close to Z308, but because of the larger shrinkage and crack resistance is poor. Welded joint strength is lower, so should not be used for parts of the welding force can be used to warm at room temperature or low temperature (up to about 300 ℃) of gray cast iron welding. AC and DC. Uses: used in less demanding strength of the welding of gray cast. Z116 low hydrogen type DC high vanadium steel used in cast iron welding defects, such as automotive cylinder, rack gear boxes, etc., can also be welding high-strength castings and ductile iron castings, weldments without preheating can be carried out after welding cutting, but the processing performance than Z508, Z308 and Z408 Z248 DC spheroidal graphite cast iron parts for welding. Z308 graphite cast iron AC and DC for thin pieces of pure nickel and processing side of welding, such as cylinder heads, engine blocks, gear boxes and machine tool guide and other important gray cast iron. Z408 graphite DC nickel-iron alloy used for important high-strength gray cast iron and ductile iron welding. Such as cylinder, engine blocks, gear and so on. Z508 graphite-type nickel-copper alloy used for AC and DC require high strength gray cast iron