Bending plastic conduit

[Munroast]

I didn't get too far with this, ordered a spring but the wrong size arrived, they tell me I ordered the wrong size, and they sent exactly what I ordered - so out of interest what size would you have ordered
its white plastic conduit with a 20mm inside dia

 

[morqthana]

I'd have bought a 20mm one from Screwfix or Toolstation for less than half the price of that one.

 

[SUNRAY]

(metric) conduit is measured by outside diameter which is why TLC show light and heavy gauge versions, mine came with white or green paint markings to indicate the difference but I don't know how typical that is.

 

[Munroast]

neither of those posts answers my question - what size spring would you buy for a plastic tube with a 20mm interal dia ?

(as for the lower prices, @SUNRAY @morqthana toolstation/screwfix is a 50 mile round trip, and TLC electrical supplies - the delevery charges would have made it more expensive)

but anyway, back to my question - what size spring would you buy for a plastic tube with a 20mm interal dia ?

 

[ebee]

I think you might have bought it from a plumbing firm rather than an electrical firm, different conventions sometimes apply.
Inside diameters versus outside diameters also sometimes apply as a fudge around from Imperial to SI units too , I mean old imperial copper tube (copper pipe as often known around here) the half inch became 16mm and 3/4" became 20mm , near similar sizes in reality if not by pure maths, as one example.

This showed up when working with a plumbing/heating firm for many years and they were "supply the immersion heater" I`d find no stat with it, so I argued that the wholesalers always supplied it with a stat and they argued they never did do. Turned out we were both correct from our own perspective.

 

[SUNRAY]

neither of those posts answers my question - what size spring would you buy for a plastic tube with a 20mm interal dia ?

(as for the lower prices, @SUNRAY @morqthana toolstation/screwfix is a 50 mile round trip, and TLC electrical supplies - the delevery charges would have made it more expensive)

but anyway, back to my question - what size spring would you buy for a plastic tube with a 20mm interal dia ?
View attachment 387375

I'd suggest you have to identify WHICH PIPE has an internal diameter of 20mm then purchase the correct spring for it.

That list is for composite (multilayer) water pipes which are very different to plastic conduit which is what the thread is all about

 

[ebee]

I will not comment on the habit of many people (around here anyways) using the term "One new pence" yet under the old £ s d would have said "one penny" .