Electrical Pipe threads

Merry Christmas
Status
Not open for further replies.
I looked into this years ago and I believe plumbing threads have 3/8 taper per foot and elect 3/4 per foot. So I have allways wondered if anyone made dies for electrical. Particularly Rigid since they make the dies I use mostly.
 
Just to reinforce what others have already posted, (i.e. that conduit uses tapered threads) ...while not an 'authoritative source", here's what the steelconduit.org web site says about it: (Q&A #13)

... the threads of both RMC and IMC [shall] be cut with a 3/4 inch taper per foot (1 in 16) per ANSI/ASME B.1.20.1 Standards for Pipe Threads, General Purpose (Inch). This applies to both factory and field threads. This is the same taper as standard plumbing pipe ...
Click to expand...
[Edit to add] Some of the confusion might be that there are two types of tapered pipe threads .. NPT and NPTF.

(NPTF = "Dryseal" -- sealant not required in plumbing applications)

That could explain what it's sometimes thought that plumbers use a "different" thread -- if they're using NPTF, "technically" they are -- although you can't easily see a differece just by looking at it; the "taper" and "thread pitch" are the same.

Jim
 
Last edited:
What is wrench tight?

What is wrench tight?

No too people are the same strength... Every at the place were I work tighten every type of threaded device until they can't tighten it any more... They also say that they know what the proper torque by feel... This isn't so,

I have put a torque wrench set at lets say 25 ft-lbs on a bolt and went out there to the bolt and showed them... It showed that it was 25... I then kept increasing the ft-lbs by 5 and trying it on the same bolt... This kept showing that it was the same all the way to 100 ft-lbs which the socket on the torque moved until with you feel the slip... This proves wrench tight isn't the way to feel that things are tight...

terminal blocks are treated the same way and they are stripped out... We need screw drive attachments to the torque wrenches...
 
Status
Not open for further replies.
Top