Diamond Core Drill Bit,BRSCHNITT 1 3/8 Inch Laser Welded Diamond Hole Saw with 5/8-11 Thread for Granite Marble Solid Block Stone Reinforced Concrete,Dry or Wet Drilling (35mm)

Used it to drill a hole in a quartz countertop for a filter tap. Worked better than I thought it would, cut through like it was butter. Fit well into my drill using a drill bit adapter.

I am not a professional by any means. I am just a cheap person who did not want to pay someone to drill extra holes in my countertops, and I own a grinder. The drill bit does all the work for you. I bought two sizes, and both performed wonderful. It is very easy to use and leaves a clean hole on dry or wet surfaces. Please make sure to pull out the cut piece after every use, or else the bit will not drill properly and will travel on you. It being the first for me, the second hole was not as clean because I thought the bit being so deep I could drill about three holes before pulling the cut piece off, big no-no. once I figures that out, all the holes but the second one were clean cuts with not jig. Make sure to start the hole in a slit angle until you make a small groove, than you can start to straighten up as your drill to avoid skipping all over your countertops.Fyi its new construction and i still need to clean up and finish touches , but besides 2 hole on the master and 1 hole on the hall restroom being done i drilled all the other holes myself. I did not have pictures of the other restroom or laundry room, but i drill quit a bit holes and it held sharp. Very great product. FYI I know the kitchen sink looks overkill but that's a 48" long sink not a regular size, and yes it still needs cleaning.

Worked great on CBS Blocks.

Bueno

It works great. I used a grinder.

works well

This bit burned up on the first hole. Total junk in my opinion. I cut holes almost every day and this bit could not even drill one hole.

I was able to cut a hole in foundation wall with a regular corded hand drill. The wireless one will die and not ha e the necessary power