half of the circumference of the workpiece w as seen from the top in fig6 and in cross section in fig7 the bending die 36 has an l shaped cut out portion 42 or aperture which defines a first flat surface 43 extending inwardly a distance from its outer circumference past the inward facing radius of the annular channel 40 and then a second flat surface 44 extending laterally outward to one side at a right angle to the first flat surface 43 a counterbore 45 extends inwardly a short distance from the first flat surface 43 along an axis tangent with the center of the annular channel 40 to define a semi circular counterbore having a radius slightly larger than the radius of the annular channel the inward end of the counterbore 45 terminates approximately at a plane corresponding to a straight line extending the through the center of the bending die fig6 the radius of the annular channel 40 is sized to receive one half of the exterior diameter of the tubular workpiece w the radius of the counterbore 45 is sized to receive one half of the sleeve element of a flared fitting at the end of the workpiece w and the flat surface 44 of the cut out is sized to receive the flat surface of the nut which is installed on the sleeve at the end of the workpiece the bending die 36 may be mounted in two different positions for different operations the rectangular recess 38 on the underside of the bending die 36 fits onto the rectangular portion 34 of.