Steel conduit wall thickness

[UNG]

BS 31 : 1940 is the spec for imperial conduit

You could always buy some from here they claim to still manufacture BS 31 conduit

 

[snowhead]

Imperial British conduit was 3/4 and 1" verses Metric 20mm and 25mm
The wall thickness was the same, give or take a thou' or 2 as the current metric is.

1" imperial is exactly(ish) the same outer diameter as 25mm, (1" is 25.4mm) we used to thread old 1" with metric dies to save using adapters which were scarce at the changeover.
The thread is not BSP, the wall thickness woulnd't take it, it's a specific Parallel conduit thread.

I did still have my Imperial dies somewhere

 

[Outspoken]

Marvo, your in SAFA so why not do it like all SAFA sparks...unwelded plastic conduit and flexible..you know, that stuff that looks like the exhaust from a washing machine..

Muhahahahahaha

 

[Marvo]

Imperial British conduit was 3/4 and 1" verses Metric 20mm and 25mm
The wall thickness was the same, give or take a thou' or 2 as the current metric is.

1" imperial is exactly(ish) the same outer diameter as 25mm, (1" is 25.4mm) we used to thread old 1" with metric dies to save using adapters which were scarce at the changeover.
The thread is not BSP, the wall thickness woulnd't take it, it's a specific Parallel conduit thread.

I did still have my Imperial dies somewhere

The unknown thread was what prompted my first question about wall thicknesses, I had a sneaky feeling that a standard BSP thread was too deep.

If you have original imperial dies somewhere and find yourself with enough time to rummage them out over the next few days I'd be very appreciative or any TPI/pitch and any thread depth info you can give. If as you say the old and new tube diameters and wall thicknesses are within a couple of thou it would make my life a lot simpler.

 

[Sintra]

Marvo the info you need might be on one of these pdf's. I don't have time to read them now but I do recall seeing it.

https://www.dropbox.com/s/dmwr5xs06syjqnh/SteelConduit.pdf

https://www.dropbox.com/s/0c94bueh9eavurp/Conduits.pdf

 

[ipf]

And probably why they only use they're seamless heavy duty conduit in hazardous area installations!! lol!! It's similar to what we used to call our seamless HD conduit , ...''Barrel'' conduit.

There is a difference in physical size between Yank conduit and UK imperial/metric conduit. Pretty sure they size by internal bore where the UK sized on OD. To be honest it's been a very long time now, since using American conduit. What i can remember is, that the 3/4'' doesn't fit UK knockouts on metal back boxes, they had to be drilled out bigger, and the lock-nuts then hit the back box accessory screw lugs!! Cost the contractor a lot of time and money, as the best part of the initial system was pulled out and his conduit stocks replaced with metric conduit!! lol!!

If I'm not mistaken, SDC, 'Solid drawn conduit'.

 

[somersetsparks]

I've got all the dies for imperial conduit, you can successfully thread 25mm with 1" BSP dies, most of our works pipe vices are old and have 1" formers, the difference is so minimal!

GLENN- You are right on taper threads usually only on gas, however I have seen them on water pipe where to lengths are joined in a coupler with no ptfe! Probably done in the 1930's