UN thread gage question - threads for high temp service

[USAeng]

we currently use a 1 1/4-12 class 2 thread that doesnt do so well... seizes up sometimes

I wanted to go to a 8 series thread and class 1 but cant seem to easily get gages for 1 1/4-8 class 1 threads

seems like the gages available are mostly class 2 and 3 threads...

does anyone know a supplier that stocks class 1 gages and also I can get a 1 1/4-7 thread gage easier than 1 1/4-8... should I go with the 7 thread or? I just saw in the machinist handbook that they recommended the 8 series for high temp. applications but I figure the 7 is pretty close... but I would still have to locate a class 1 gage in that too

we are also going to be trying a few different types of antiseize we currently use loctite high temp but will try desco and jet lube

thanks for your thoughts

 

[unclesyd]

What is the high temperature?

What are the materials involved?

You might want to check with Southern Gage. If they don't have the gage to meet your requirements they will know who does.

http://www.gsgage.com/index.asp

 

[CoryPad]

For thread gages, these two places will be able to supply what you need:

http://www.johnsongage.com/

http://www.greensladeandcompany.com/

 

[Duwe6]

And if you are only gaging the male threads for fit-class, look up "three-wire thread measurement" in the "Machinery's Handbook", or try googling it. Just need a set of wires at about $30, and a good micrometer.