UNS and UN thread

[M Code]

I got drawing that mentioned the thread is 6.925 – 8 TPI UNS as per ANSI/ASME B1.1 . However, when I back to the book I didn’t find that in the tables but anyway the drawing mention all required dimensions: major, minor and pitch. My question is the UNS profile is the same of UN profile of ANSI/ASME B1.1?

 

[sfriedberg]

Yes. The S for Special is for non-standard pitch diameter and pitch combo. UNS uses the UN thread profile, and thread depth (etc) can be taken from an UNC or UNF thread of the same pitch.

 

[M Code]

Yes. The S for Special is for non-standard pitch diameter and pitch combo. UNS uses the UN thread profile, and thread depth (etc) can be taken from an UNC or UNF thread of the same pitch.

Is that mean I can use 8 UN insert + 8 UN thread roller gage?

 

[sfriedberg]

8UN insert, yes. Not sure what you mean by "8UN thread roller gage". Is this an adjustable pitch diameter gage with "fingers" of 8UN thread profile? (I've seen these as machines/gages with two fixed locators and one moving locator.) If so, probably yes, but helix angle decreases with increasing PD, so there might be some systematic measurement error to compensate for as the gage "fingers" will engage with the cut thread very slightly differently at different PD.

 

[oppster]

An 8 un insert will be fine, it is the pitch that has changed from standard. 8un roller is also the same, you are just making a 6.925"(od) thread with a pitch of 8

 

[oppster]

Also, we have a license for threadpal, which will give you dimensions over wires etc etc..
Here is the link

Contact Support

Hope this helps

 

[Bobw]

Also, we have a license for threadpal, which will give you dimensions over wires etc etc..
Here is the link

Contact Support

Hope this helps

Threadpal is pretty sweet.. I put off buying it for years.. Suffered through googling, and messing
with the Machinery Handbook, looking up formulas, crunching #'s, trying to remember where I left
this spec or that spec..

And then I got a couple of jobs that had a bunch of oddball threads. 11/16-18 J thread..
.925-16 UNS.. Stupid stuff like that... So.. There was going to be a lot of wire number
crunching. So I said screw it, and bought it. I think it was $50 back then.. Paid for
itself within a week, and here we are almost a decade later, and I still use it quite a lot..

Doesn't hurt that it was made by one of our members here.

Good stuff.

 

[oppster]

We do random american threads all the time here in the UK. Very rare i open up my zeus book these days.

Hats off to that member that made it! Well done!

 

[twr]

Hi another threadpal user very happy with it! Has saved me alot time. Also as Bobw said he is also a member of PM forum.