Abstract: Tail-end fins are normally produced with the pierced shell due to the fact that deformations of the outer layer metal and that of the inner layer are not consistent to each other.Such fins would very possibly get into the pipe to scratch the mandrel surface and the internal surface of the pipe during the MPM rolling process.Moreover, if the fins fall down between the mill stands, the rolls would be jammed.But now, such troublesome fins have been almost prevented by means of optimizing the piercing tools (the guide shoes and the plug), and adjusting the rolling parameters, resulting in improvement on pipe quality, and enhancement of services spans of both the mandrel and the roll.