On 27 Oct, 23:49, John Stumbles wrote:
On Wed, 24 Oct 2007 18:00:14 -0700, ian wrote:
I need to run a pipe 68mm diamater or possibly 110mm through the wall
of my garage. The wall is timber clad with corrugated iron. The founds

holesaw?

Unless there is a compelling reason to do otherwise, it would be very
much easier to cut a square aperture in the corrugated iron (using an
angle grinder), then fit a collar around the pipe.

If you wanted to be fancy you could use an angle grinder to cut a
closer-fitting hexagon or octagon.