Polytank loft tank - 22mm hole saw

[anta]

About to fit a 50 gallon polytank in the loft. Instructions say I need 22mm, 27mm and 29mm hole saws. Plumbers kits have the 22mm and 29mm, but I can't see a 27mm anywhere. Not even as an individual item.

Any suggestions?

Ant

 

[kevindgas]

try B&Q they sell various hole cutters if you can get 27 then a 25 or 26 will cut the hole then carefully open it out with a stanley knife.

 

[mikegm]

I was prepareing an expansion cistern, and I'm pretty sure it was the 27mm I was short of. I visited my local 'hardware' store, the tools department, and bought one there fairly cheaply.

 

[TicklyT]

An Imperial size cutter would be the right size. 1-1/16" = 26.9875mm, which is close enough to 27mm for most jobs.

IME hole saws tend to cut oversize anyway - generally, the cheaper the hole saw, the wider the tolerance.

To open out a fractionally undersized hole, my weapon of choice is a half-round file.