PURPOSE: To manufacture a small diameter resistance welded tube which is used for a structural part in an automobile and machine and which is superior in fatigue characteristics in a bent part.

CONSTITUTION: In a small diameter resistance welded tube with a bent part worked in a circular-arc shape from a part or the entirety of a straight tube, after being bent smaller by 5-10% than a prescribed bending radius, the tube is bent in the reverse direction larger by 5-10% than a specific bending radius. Consequently, without quenching or tempering in the intermediary process or without stress relieving annealing, a small diameter resistance welded tube with superior fatigue characteristics in the bent part is manufactured by regulating a bending method, without causing the problems in industrial productivity and economy.