PURPOSE: To adjust surely the radial projecting position of a tool to a specified position with a simple construction by providing a projecting arm to an annular plate, and screwing a feed screw shaft which moves radially forward and backward grooving tools into the tapped hole of the projecting arm.

CONSTITUTION: A projecting arm 21 is formed at the outside circumferential part of a movable plate 11 and a tapped hole 23 is formed to the arm 21. The axial line 23A of the hole 23 exists extensionally in the plane inclusive the plate 11. A handle 25 having a feed screw shaft 27 is attached to the hole 23 and the semispherical top end 28 of the shaft 27 is detained in a suitable place 29 of, for example, the body of a cutting machine to be attached with said die head. When the handle 25 is thereupon operated to rotate, the plate 11 can be turned relatively with a plate 13. As a result, tool holders 10, hence rollers 20 are advanced radially by the distance of l2 to positions 20' and the tips of the rollers 20 are brought into contact with a work such as a pipe 100 or the like.