The pieces b or d, Fig. 58, could also be made by the rolling dies in Fig. 60. The arbor a that the cup or tubing is placed on is considerably smaller than the inside of the cup or tubing, to allow the removal of the finished part. The female roll b is attached to the cross-slide of the rolling lathe or the roll dies can he used in an ordinary lathe by gripping the male member a in the lathe chuck and the female roll in the tool post of the lathe. In operation the cup or tube is placed on the revolving roll in the chuck and the roll b is brought to bear against the work. The friction between the two rolls and the work is sufficient to cause the work to rotate, and as the cross-slide of the lathe is moved toward the center of the lathe the beading or form is transferred from the rolls to the work.

Fig. 60. Rolling Die.