116 0r 118mm hole saw

[Lazurus]

I need to drill a 116 or 118mm hole in a plastic pumping station tank to insert a 110mm invert soil pipe, this is the suggested size from the supplier to match the rubber seal supplied with the kit. Despite best attempts via Google I am unable to find one, or an adjustable this size - any suggestions or work arounds?

 

[Gordon Tarling]

There's plenty of adjustable fly cutters that will cut that size, if they'd do the job.

G.

 

[Spectric]

This one from screwfix Erbauer Adjustable Holesaw with Cowl 29cm 9 Piece Set

 

[Ozi]

I use an 111mm hole saw like the one on the same page Spectric posted. Works very well if you don't over shoot and dig in the two side cutters

 

[Spectric]

Re-reading this and with your plastic tank, how rigid is the tank because if it is to flexable you could have more problems. In this case use a hole saw like Hole Saws | Hole Cutters | Drilling | Screwfix.com

 

[Sheptonphil]

117mm cutter for a standard arbor.

 

[Robbo3]

I wouldn't bother with a hole saw for a one off job. Mark it & cut it out with a jigsaw using a fine tooth blade.

 

[Lazurus]

Yes i think the flexibility is going to cause issues so the jig saw may be the best answer, thanks for all the suggestions much appreciated.

 

[Sheptonphil]

If you’re going down the non hole saw route, I’d mark it out and use a pad saw, a jigsaw on material too flexible for a hole saw will never produce a round hole.

 

[xy mosian]

If you’re going down the non hole saw route, I’d mark it out and use a pad saw, a jigsaw on material too flexible for a hole saw will never produce a round hole.

I think a fair attempt could be made with an up cutting blade in a jigsaw. That is cutting towards the jigsaw plate. I would use a pad saw, perhaps with metal cutting blade, again cutting on the pull stroke.
geoff

 

[Lazurus]

A hacksaw blade in a padsaw should fir the bill thanks everyone

 

[xy mosian]

A hacksaw blade in a padsaw should fir the bill thanks everyone

For a really clean edge, cut with the blade short of the line and trim with a sharp knife.
geoff