Abstract: Apparatus for friction texturing textile yarns includes a cylinder (1) rotatable about its longitudinal axis on a base plate (2). The outer surface of the cylinder has regularly spaced friction surfaces (3) with grooves therebetween, and a spirally shaped outer cover (6) containing pegs (5) which project radially into the cylinder and engage grooves (4). The cover (6) has a cylindrical collar (10) having a yarn guide (9), the collar being movable along the axis of the cylinder and held in a desired position with a set screw (11). The top of the cylinder (1) is covered with a disc (13) having a projecting annular flange.Yarn is guided round the cylinder (1) by the pegs (5) and false twist by friction is imparted to the yarn.