Abstract: A measuring attachment is shown for use on a lathe or other machine tool which includes a pair of parallel bars or slots, one associated with the saddle of the lathe and the other associated with the cross slide. Mounted upon the parallel bars (or within the slots) are a pair of blocks each including a latching arm that latches each block to one bar or the other. A single stop is mounted on the first block, while a group of several stops may be mounted upon the second block. When an outer diameter is to be cut, the several stops may be attached to the bar mounted upon the radially fixed saddle. In this arrangement, the shortest of the several stops is used as the center line reference against which the single stop engages. The longest of the several stops provides the reference for the first outer diameter cut. When an inner diameter cut is to be made, the block mounting the several stops may be attached to the bar which is mounted upon the cross slide.