On 22/08/2018 11:16, David wrote:
Looking at diamond drill sizes they are 38mm and 52mm, so logically you
use a 52mm core drill for 40mm waste.

Just double checking as it seems like a lot of over size...

Don't forget that 40mm is the inside diameter of the pipe. Depending
upon type, it may be up to 44mm outside diameter.


--
--

Colin Bignell