Bosch HC8555 4-Inch x 17-Inch x 22-Inch SDS Max 1-Piece Core Cutter

I bought this bit thinking that it would work well for me in steel reinforced concrete. There were no reviews on it and I am new to this. I have used this bit and the 2" bit as well several times now. If you are boring through pure concrete or concrete block, it goes through pretty quickly. For thick concrete, I found that it was easier to bore down about 3/4" to 1" then work the bit sideways to break off the piece. Since there are no slots on the sides of the drill bit, you basically have to bang out the piece just broken off. If you bore deeper than 1", then you will have a heck of a time getting that piece of concrete out of the bit, because it binds between the outside of the bit and the center bit (not shown in the picture). Last, if you hit rebar, forget it. This bit won't touch that. It did break up some of the wire mesh used in one hole, but did not go through that either. I had to get a friend to torch out the rebar and the mesh. I was simply putting drains in my garage floors.

If you are boring thru concrete block, then this bit will serve you well assuming there was no steel put into it.

One last thing, the bit simply pounds down using the Bosch Hammer Drill. It does not turn. So, you do not have to worry about it catching on things. Because it is simply pounded in, the initial edge will be a little ragged for about 3/8" around the outside of the hole. Hope that helps others.

Previous reviewer's information on this bit is incorrect. This bit is a designed to be used in a rotary hammer, not a chisel. It works very well at this job - won't cut through rebar (the carbide teeth catch in it, and you may damage the bit if you really try to push through it), but through any kind of masonry (I've used it on concrete, block, and brick) it moves very quickly and leaves extremely clean holes. No blowout in brick at all, great for making clean vent holes, etc.