Abstract: A two-for-one twisting spindle with a compressed air operated threading device is provided. The thread is feed via a jet of compressed air through a thread feeding channel of a thread storage disk. At the outer opening of the thread feeding channel a first deflecting surface is provided which is attached to the underside of the turntable. The first deflecting surface is provided with a upwardly curved second deflecting surface which is essentially convex. These constructive measures at the outer opening of the thread feeding channel ensure that the jet of compressed air exiting from the outer opening of the thread feeding channel has a certain vertical width h and that the radius of curvature R of the second deflecting surface is such that the ratio of the radius of curvature to the width h corresponds to R/h.gtoreq.3. This ensures that the jet of compressed air is deflected in an upward direction essentially vertically with the aid of the so-called Coanda effect.