I think i have found an easy to get source for those looking for and having trouble finding true 1" conduit in the usa my local Manards (big box hardware/lumber building center) has it so i am betting that others would stock it as well… it is listed as 3/4" ridged conduit (not EMT conduit) (Wheatland Tube Company 3/4" x 10’ Rigid Conduit) and sells for around the $20.00 per 10’ …
this is there printed specs:
Trade Size 3/4" inch
Actual Outer Diameter 1 inch
Actual Inner Diameter 13/16 inch
Galvanized Steel
i have not measured or even bothered to figure what thickness this makes it but i did visit the store to test fit one of my printed parts and found it to be really hefty and seemed very rigid.
hope this helps some of you out but someone should also verify this to be true.
Www. Speedymetals.com worked great for me.
The US options are 3/4" ID pipe (which is 23.5mm OD) or 1" OD tubing (which is 25.4mm OD). Unless you have some non standard rigid emt, it isn’t right.
Tubing is stock made to build something and so it is measured in OD. Pipe is meant to hold stuff inside so it is measured in ID. 3/4" rigid emt is threaded on the outside, so it has a particular OD, but it isn’t one of the sizes (IIRC, it’s too small for 1").
I have measured some pipe a while ago at 1.05 inches which is too much error. So it’s definitely not predictable, depending on the type. I’m skeptical about rigid conduit too. Maybe one brand at one location on one day might be close enough but calipers are the only way to be sure, and you might get lucky.