5/8-24 UNJEF bottoming tap or ID thread tool

[robert123]

I need a tap this size. Does it exist or is it custom? I see quite a few 5/8-24 but no J thread. Or an ID threading tool on a lathe could work.

 

[L Vanice]

According to this description of UNJ threads, a normal 5/8-24 UNEF tap is the tool to use, but you may need an oversize tap drill to clear the male 5/8-24 UNJEF part.

What's The “J” In UNJ Screw Threads?

Thread Check provides important information about UNJF threads, UNJ threads and UNJC threads.

www.threadcheck.com

Larry

 

[Milland]

I need a tap this size. Does it exist or is it custom? I see quite a few 5/8-24 but no J thread. Or an ID threading tool on a lathe could work.

Depending on depth of thread, you might use a threadmill as a boring tool, like the single profile cutters at the top of this page: https://sct-usa.com/wp-content/uploads/2019/05/2019_tm_sptmunj.pdf

 

[SeymourDumore]

As mentioned, for internal J threads the only variation from the standard is the minor diameter, which is larger to accommodate the root radius on the male thread.
As a result, there is no such thing as a UNJ tap.
Bore the minor to the spec ( for a .6250-24 UNJEF it is .5904-.5844 ) and tap with whatever will get you the depth.