Abstract: Internally-burring is regarded as a key operation step for manufacture of the HFW steel pipe.During such a process,build-up of molten metal may be formed,due to improper adjustment or maloperation,which would in turn negatively influence the burring quality.Elaborated in the article are the types of build-up formed on the cutter or cutter bar as used for internally-burring the HFW pipe.Furthermore,causes for the build-up are investigated,and method for on-line observation and judgment of the build-up,and preventative actions are proposed.