... pores, overip, undercut welding defects such as ultrasonic testing, requirements of welding GBl1345 grade II standard. 4,steel anti ... to 1 / 1000, such as nonstraightness meet the requirements, correction, especially the polygon rod must ensure nonstraightness. ... directly affects the quality of galvanized, galvanized galvanized requirements according to national standards, after plating the surface is ...