You did ask for the best. A dry diamond core can mounted on a
right angle grinder. Clean and efficient.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Robert Green" wrote in message
...
What's the best way to punch a 2" hole for a drain pipe through
a cinder
block wall?

I've researched a variety of suggestions from a hammer and a
star drill, to
drilling a ring of small holes in a circle with a carbide bit
to renting or
buying a diamond tipped core bit. What's the best way of doing
it so as
NOT to crack the block?

--
Bobby G.