This invention relates to apparatus for manufacturing tubes by the helical coiling of a strip into successive convolutions. The strip is preferably of a corrugated sheet metal. The coiling means of the apparatus comprises a plurality of non-driven freely rotatable and radially adjustable guide rollers adapted to guide and support the strip during the formation of a convolution. These rollers are arranged on a circle so that they engage the convolution at its outside. Arranged at the point of the strip entry into the coiling means is an inner and an outer connecting roller, the inner connecting roller positioned within and the outer connecting roller positioned outside the circle on which the guide rollers are situated. The connecting rollers have the purpose of joining a convolution after its travel past the guide rollers to the incoming strip so that convolution and strip overlap each other. By controlling peripheral rotational speed of the connecting rollers and providing the connecting rollers with various surface configurations, the joint between the incoming strip and the just formed convolution can be controlled to insure a proper joining therebetween as well as dimensional control of the diameter of the tube being formed.