Locating Holes, Drilling and Tapping in Cast

Opens with the operator's laying out a bolt circle with eight holes. The method of locating the center of the bolt circle and the centers of the various bolt holes, together with the way they are marked to guide the drill press operator, are shown. After all the holes have been drilled, a tapping chuck of standard make is used to tap two holes for set screws. The method of setting the machine for this operation and the precautions the operator must take are shown in detail.