METHOD FOR MAKING BIMETAL HELICALLY FINNED TUBE

摘要

A method for making bimetal helically finned tube includes preliminary mechanical treatment of outer surface of bearing tube and cross-screw rolling of fins. Preliminary mechanical treatment is carried out through application of screw groove at outer surface of the bearing tube. Pitch of screw groove is set as equal to fin spacing, and fin rolling is carried out in such way that spaces between the fins are over against the groove.