The work A shown in Fig. 3 is a steel flange which is to be recessed at B in order to provide the necessary clearance for the threaded portion G. In this instance the cut-off slide was used during the progress of the work, so that a considerable overhang from the turret was required. Strictly speaking this is not an eccentric tool, for the various parts of the body are concentric, but by a reference to the upper part of the illustration it will be seen that the center-line VW of the recessing tool does not coincide with the center-line TU of the spindle. Now as the tool-holder F revolves on the center line VW, it is evident that the path of the tool D, as it swings, will be eccentric to the center line of the spindle. The body L is of cast iron and is mounted on the dovetailed turret face, being securely held in position by the gib M and the screws N. The tool-holder F is of tool steel and is turned down at K to a running fit in the body. The end Q with the screw and washer 8 and R acts as a retainer to keep the tool-holder in position. The tool D is of round section with the cutting end so shaped that it will cut the recess properly. A set-screw E holds it in position. An oiler 0 is located in the body and distributes the oil to the bearing through the oil groove P. An operating handle G is driven into the holder, and is located between the'pins H and J which act as stops. As the lever G is operated, the tool D, starting with slight clearance at the bottom of the hole, moves gradually upward and outward until the full depth of cut has been reached. At the completion of the cut the tool stands in the position shown in the illustration. The action of this tool was perfectly satisfactory, and as it is comparatively simple in construction, the cost of building was not excessive.

Fig 3. An Eccentric Recessing Tool for the Turret Lathe.