includes the diamonds in the lean edge, about 7-8 stones. Does not think a 2 1/2 inch core can be drilled deeper than 4 inches. These diamond drills at one inch diameter will go through 4 inches of granite in 10 to 15 minutes. The feeding on the form is by hand. The chucks are as follows: [diagram] shaft into chuck. can make these chucks in 2 weeks extra. water flange dollar tube. how rig holding diamonds. These chucks must not move rapidly otherwise the diamonds will come out of their setting. The diamonds will determine the angle of cutting and the chucks should be loose enough to follow the diamond lead. Diamond drills will work very well in certain materials are hardly at all in others. Cuts a quartz crystal about as easy as marble but in a quartzite very difficult. A granular silicious material it would also go through easily but in some of the silicious stuffs will not work at all.