Ideally I need some 2G white surface boxes in PVC with 20mm knockouts

[telectrix]

Step drill??
Be kind I’ve led a sheltered life

a cone cutter, but stepped at various diameters.

 

[Ian1981]

a cone cutter, but stepped at various diameters.

Oh right yeah I’ve a cone cutter.
I use it to make say 20mm holes a bit larger say to 25mm etc

Step drill! God you oldies crack me up

 

[Risteard]

Oh right yeah I’ve a cone cutter.
I use it to make say 20mm holes a bit larger say to 25mm etc

Step drill! God you oldies crack me up

I have cone cutters and step also. If I want a 20mm hole though I'd use a 20mm holesaw - don't see the point of stepping up to 20mm.

 

[telectrix]

saves having to clean the partly melted plastic out of your hole saw.

 

[Pete999]

Oh right yeah I’ve a cone cutter.
I use it to make say 20mm holes a bit larger say to 25mm etc

Step drill! God you oldies crack me up

What's wrong with calling it a step drill? a cone cutter is different from a stepped hole cutter / drill whatever.