On 14 Nov 2006 13:17:17 -0800, "dean" wrote:

Ok I know i can drill a whole load of little holes in a circle and then
knock it out, but is there such a thing as a 4" drill bit that will do
this more easily?

Thanks!

DeanB

Drill a series of small holes and then punch the core out. Purchase
a half round ******* file. The file isn't meant for concrete but will
do a nice job in smoothing and accurizing the hole. You may have
to throw the file away when done, but it will work.