1. The steel strip shall be annealed and the surface roughness shall be 6.3μm；
2. The powder size should be around 0.25mm；
3. There is a requirement for the composition of the cored wire, and the calcium in the calcium silicon cored wire is required to higher than 28%；
4. The error of powder weight shall not exceed the specified limit；
5. The hasp of cored wire is compact, no powder leakage is allowed during feeding；
6. Indicate the weight of the cored wire, the length of the cored wire, and the weight of the iron plate；
7. Powder must be dry, with moisture content less than 0.5%.