5/16-14 thread J/P problem..Can I make them work?

IIRC, some of the older Schons had a 'different' pin in that the shape of the thread, the minor diameter or the major diameter was different from 'the norm'.

Depending on how deep your JPs are, you can run a 14 thrd. tap in & out and that should fix the problem.

> KJ is correct yet again,the Schon version of the 5/16-14 is typically about .010 UNDERSIZED on the Major (across the top of the threads) and Minor (at the bottom of the thread groove) diameters from the standard version.

Without a tap,there is NO WAY a Schon shaft fits anything other than a Schon (usually about .302). However,the industry in general uses a true 5/16 (.3125) tap which is why a new Predator fits them every single time.

I didn't know this early on as a Schon owner,and because of that it took me 5 tries before Bill McDaniel finally found me a set that fit ,and it also caused me to have to take my McDaniel jump cue butt back to him and have him actually fit it to a Schon shaft.

Also,putting a true 5/16 pin in a lathe and filing it down will not work,the flats you created with the file will bind up as sure as the sun is coming up. The only way to make one fit a hole tapped with the .302 tap is to take the pin out and "chase" the threads on a lathe,those with weak machining skills need not apply.

You basically have one option. The way to go is to take the JP's to a cuemaker and have him open the threads up with the tap. I say this because the 5/16-14 is an oddball tap not available just anywhere,and is usually about 40 bucks shipped from Atlas or Prather's. If this is not objectionable,by all means pick one up.

Keep in mind that by doing this,it will affect the thread fit of your shafts. Hope this sheds a little light on the subject,Tommy D.

triley41395 said:

OK, Here is my problem,I have 3 Schons one is from the late 80's and two are from the late 90's. I also have an extra shaft(Nova). All the shafts interchange with all 3 cues. I bought joint protectors for all of them but the older shaft and the Nova shaft J/P's will not fit.I ordered them all 5/16-14 for Schons thinking since all the shafts would all interchange that the J/P's would also. My question is how can I make the J/P's fit by altering only the J/P's. Is it the top of the thread, the bottom of the thread, or both causing them not to fit? Also I'm not sure if it matters but the older Schon shaft is not marked Schon, it just has the silver ring like one so it could be from a different maker. Any help or suggestions will be appriciated. Thanks Lee

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Are the threads on the JP's metal or plastic?

In all honesty, you may have been a little hasty in pulling the pins from the JPs. The problem here is that you're not going to find that under-size pin mtrl.
It's going to have to be made (and no, Schon won't sell you any).

It can be done. Just find a decent machinist. Have him start with a pre-made 14 thrd. pin (maybe brass). Mount it in the lathe, 'pick-up' the thread and take a .005/.006" cut in the existing threads and you should be at where you need to be.
I hope you know this machinist real well though, because otherwise, this may not be cost effective.

I'm not even going to suggest that you tap the 'tight' shafts. You wouldn't like the way they would fit on the small pin after that. WAY too loose.
No, don't mess with the shafts. Those particular shafts are getting hard to come by.

About the only other suggestion I can offer is to call Connecticut Cue Parts.
Maybe he's got some under-size from an oops-run.

Man, all for a set of JPs.