UNJ series thread
UNJ series thread
(OP)
First time I've come across a UNJ-series thread outside of the aerospace world...
...the center lock, single wheel nuts that we purchase have a UNJ internal thread. Looking at what info I can find, and going from memory, I'm trying to confirm that a UN series external thread will work in a UNJ series internal thread, but a UNJ series external thread will not work in a UN series internal thread. This because the UNJ external has the larger root radius, and would cause interferrence, but the UNJ internal thread only has a larger minor diameter.
Can anyone confirm this?
...the center lock, single wheel nuts that we purchase have a UNJ internal thread. Looking at what info I can find, and going from memory, I'm trying to confirm that a UN series external thread will work in a UNJ series internal thread, but a UNJ series external thread will not work in a UN series internal thread. This because the UNJ external has the larger root radius, and would cause interferrence, but the UNJ internal thread only has a larger minor diameter.
Can anyone confirm this?
-Dave
Everything should be designed as simple as possible, but not simpler.





RE: UNJ series thread
There is also a forum here on fastener engineering in the Structural Engineers section. They might be of more help.
RE: UNJ series thread
The larger J radius is only used on the external thread. The J nut has the larger minor dia to clear. A J nut and bolt use Class 3 threads to make up for the loss in engagement area.
A J nut will fit a UN bolt but they suggest caution because of the loss in area. I think most bolts are already Class 3 however.
Even though a J nut is supposed to be used with a J external thread, they say that many users have used standard nuts without any problem.
Hope this helps.
RE: UNJ series thread
Much appreciation...I'll check out that fastener forum too.
-Dave
-Dave
Everything should be designed as simple as possible, but not simpler.