The large dia stepped mandrel is hardened & ground between centers. It is indicated in the lathe & remains in place through out the grinding process. Notice the jack screw between the two clamping screws at both ends of the fixture. The jack screw opens each end because of the saw split to allow the fixture to be placed on the mandrel. The two locating pins pass through the bottom of the fixture after securing the connecting rod. All parts of the fixture are square & accurate within .0002.
