... over a form until the steel is shaped into a hollow tube. The seamless pipe is then ... and so onProduction technologySeamless steel pipeWelded steel pipeSurface treatmentPolishing or notThe stainless steel barstandardASTM,GBmaterial201,202,301,304 ... ,316,316L,316LN,317,317L,309,309S,310,310S,430,409specificationRoundSquarerectangle 304l stainless steel tube ...