Stone Boss Premium Wet/Dry Bits for Granite, Marble, Onyx, Engineered Stone and all Similar Materials, Sizes 1" thru 2" with 5/8"-11 Threaded Arbor

I tested the 1 3/4” bit today in 1 1/4” flagstone. It worked well. The holes were clean cut on both sides with very little chipping on the back side. Technique is important. To start low speed, at an angle to control the bit, gradually rotating to full contact. After full contact and the bit is not walking, changing to high speed, keeping stone wet. Took about 2-3 minutes per hole. The pics are front and back sides of same two holes.

great