3/8 x 10 pin and cue sellers

[7stud]

Sometimes I see pictures of cues for sale, which seem to have a 3/8 x 10 modified pin, yet they are advertised as a 3/8 x 10 pin. Why is that? Are the cue sellers ignorant?

Here is a picture that shows the difference between the two pins:

https://www.dzcues.com/images/joints/IMG_3047a.jpg

To me, it seems pretty easy to identify the difference: one has a pointed nose, the other has a flat nose; one has threads that are cut deeper, the other has a fatter "forearm" and shallower threads; one has threads that appear to be closer together.

 

[garczar]

Sometimes I see pictures of a cues for sale, which seem to have a 3/8 x 10 modified pin, yet they are advertised as a 3/8 x 10 pin. Why is that? Are the cue sellers ignorant?

Here is a picture that shows the difference between the two pins:

https://www.dzcues.com/images/joints/IMG_3047a.jpg

To me, it seems pretty easy to identify the difference: one has a pointed nose, the other has a flat nose; one has threads that are cut deeper, the other has a fatter "forearm" and shallower threads; one has threads that appear to be closer together.

Easy there brother. Yes, some people do not know the difference. You have to be very clear when buying/selling any 3/8x10 pin cues.

 

[cubswin]

Nose style of pin means nothing when it comes to the thread style.

 

[Texas Carom Club]

They can screw together so who cares

 

[jimmyco]

Are you syncing with ColoDC?

 

[ShootingArts]

One thing not acknowledged is that we are looking at pictures of two different grades of threads. Normal threads are not designed to locate anything radially so naturally they do a poor job of that. The modified threads do a better job but still don't match the quality of a piloted joint.

There is nothing other than difficulty of fit and assembly preventing a smaller hole before threading and getting a better stronger fit with the standard thread. The full threaded joint which starts getting very hard to put together at 75% fit in metals, will be a stronger fastener than either joint shown here. Then you can provide piloting by a different means and have a stronger joint in all respects.

A close look will show that these threads, male and female, aren't perfect matches. This is one reason for building a joint with a smaller number of threads. I ran into this issue years ago with acme threads. Buying ten, twelve, or even twenty foot lengths of two inch OD rolled acme threaded stock, it sometimes wouldn't thread properly or even at all into two and a half inches of female threads. The problem was simple, tolerances. Acme threads of the size we were using were only required a fit to one inch of female threads. When we needed two and a half inches of thread contact we needed to go to a higher grade of thread than standard grade threads.

We were catch-22'ed, one inch of threads didn't give the strength we needed in the material being used for the female threads, there was no guarantee that any batch of threaded bar would fit a longer female section. A redesign was required.

In a pool cue the best design is a floating pin and separate pilot. Trying to make threads locate radially is a recipe for a headache especially when there are multiple shafts for one cue. Many cue makers are creating headaches for themselves because they are trying to make screw threads do something they were never meant to do.

Hu

 

[7stud]

They can screw together so who cares

I have not found that to be true the one time I tried to mix and match:

Cue extensions: how tight should the fit be?

Hi, I bought an X5 extension for my cue: https://www.pooldawg.com/x5-extfx5b-extension Before purchasing I inquired if the 3/8 x 10 extension would fit a modified 3/8 x 10 pin on an OB cue, and I received a reply that said they tested the...

forums.azbilliards.com

 

[7stud]

One thing not acknowledged is that we are looking at pictures of two different grades of threads. Normal threads are not designed to locate anything radially so naturally they do a poor job of that. The modified threads do a better job but still don't match the quality of a piloted joint.

There is nothing other than difficulty of fit and assembly preventing a smaller hole before threading and getting a better stronger fit with the standard thread. The full threaded joint which starts getting very hard to put together at 75% fit in metals, will be a stronger fastener than either joint shown here. Then you can provide piloting by a different means and have a stronger joint in all respects.

A close look will show that these threads, male and female, aren't perfect matches. This is one reason for building a joint with a smaller number of threads. I ran into this issue years ago with acme threads. Buying ten, twelve, or even twenty foot lengths of two inch OD rolled acme threaded stock, it sometimes wouldn't thread properly or even at all into two and a half inches of female threads. The problem was simple, tolerances. Acme threads of the size we were using were only required a fit to one inch of female threads. When we needed two and a half inches of thread contact we needed to go to a higher grade of thread than standard grade threads.

We were catch-22'ed, one inch of threads didn't give the strength we needed in the material being used for the female threads, there was no guarantee that any batch of threaded bar would fit a longer female section. A redesign was required.

In a pool cue the best design is a floating pin and separate pilot. Trying to make threads locate radially is a recipe for a headache especially when there are multiple shafts for one cue. Many cue makers are creating headaches for themselves because they are trying to make screw threads do something they were never meant to do.

Hu

I didn't understand much of that--but I'm guessing that you don't like 3/8 x 10 modified pins. Which pin do you like?

 

[Texas Carom Club]

i have, having owned both and screwing them together

 

[Michael Webb]

The 3/8x10 is just another Bastard screw that the pitch will vary depending on where the Cue maker buys his screws. The olde style has a .281 minor between the threads as a standard. But some suppliers have had them made with a thicker minor to accommodate the existing tap in the Industry.
Schmelke offered these once, I don't know if they still do or not.
The modified, also pretty much created to accommodate the existing tap in the Industry has a minor of .306 to .308 also depending on the supplier. For the most part, it's pretty easy to visually tell them apart.
Should they be able to interchange???
that's going to depend on who you ask. But if the Cue maker has the correct tap, or if he uses live tooling for the standard 3/8x10, then IT SHOULD NOT fit the modified because the hole is much smaller than the listed 5/16" hole. Over .020 smaller. That's a huge difference.
Will there ever be just one again. NOPE! I don't see that happening. The Cue maker is going to use what he wants for his cues, and for sanding purposes what his mandrells are made for.

 

[maha]

thats why i always stuck with 5/16 14 thread . as then i have all my shafts and butts from even different makers all interchangeable. as long as you get the same sized joint which most all do.
i dont buy specialty pin cues another reason is you become limited on who can make a shaft for your butt that fits.

 

[ShootingArts]

I didn't understand much of that--but I'm guessing that you don't like 3/8 x 10 modified pins. Which pin do you like?

Bearing in mind I haven't looked at a lot of joint types, I use a plain 3/8-10. Common as dirt, works well, you don't get repetitive motion disease like tightening some of the 5/16" joints can give ya! I'm joking about the five-sixteenth pins but they do seem to take forever to put on and take off.

I don't care much about what pin is used as long as the total joint is designed to do it's job. When I see threads alone trying to locate something radially I get skeptical. The old rule of thumb for a screw thread was that it took seven times around the center for maximum strength. More than that or a couple more for insurance are a waste of time every time you have to open or close that joint. Less threads are weaker than the joint could be, but that doesn't mean it isn't strong enough!

I had a few ideas for a joint but never got around to trying them. Nothing revolutionary, minor changes.

Hu

 

[Ssonerai]

One thing not acknowledged is that we are looking at pictures of two different grades of threads. Normal threads are not designed to locate anything radially so naturally they do a poor job of that. The modified threads do a better job but still don't match the quality of a piloted joint.

There is nothing other than difficulty of fit and assembly preventing a smaller hole before threading and getting a better stronger fit with the standard thread. The full threaded joint which starts getting very hard to put together at 75% fit in metals, will be a stronger fastener than either joint shown here. Then you can provide piloting by a different means and have a stronger joint in all respects.

A close look will show that these threads, male and female, aren't perfect matches. This is one reason for building a joint with a smaller number of threads. I ran into this issue years ago with acme threads. Buying ten, twelve, or even twenty foot lengths of two inch OD rolled acme threaded stock, it sometimes wouldn't thread properly or even at all into two and a half inches of female threads. The problem was simple, tolerances. Acme threads of the size we were using were only required a fit to one inch of female threads. When we needed two and a half inches of thread contact we needed to go to a higher grade of thread than standard grade threads.

We were catch-22'ed, one inch of threads didn't give the strength we needed in the material being used for the female threads, there was no guarantee that any batch of threaded bar would fit a longer female section. A redesign was required.

In a pool cue the best design is a floating pin and separate pilot. Trying to make threads locate radially is a recipe for a headache especially when there are multiple shafts for one cue. Many cue makers are creating headaches for themselves because they are trying to make screw threads do something they were never meant to do.

Hu

As a sometimes machinist i understand and agree with most of what you posted. IOW, (for machinists) "Screws provide spring tension. Dowels locate"

However, for cues, i simply don't like metal in the joint. Sleeve/collar or pin. So piloted in the accepted sense is not a reasonable option.
I'm nobody, certainly not "known" and barely make a few cues/yr. But i know my druthers.
So mine are based around G10 3/8" -10 modified, and i let the smooth barrel project above the face of the butt about .200"
The shafts are drilled for a close fit on the minor dia, and a snug fit on the barrel as the shaft/butt match up tight.

One more way to complicate a simple joint.

smt

 

[ShootingArts]

As a sometimes machinist i understand and agree with most of what you posted. IOW, (for machinists) "Screws provide spring tension. Dowels locate"

However, for cues, i simply don't like metal in the joint. Sleeve/collar or pin. So piloted in the accepted sense is not a reasonable option.
I'm nobody, certainly not "known" and barely make a few cues/yr. But i know my druthers.
So mine are based around G10 3/8" -10 modified, and i let the smooth barrel project above the face of the butt about .200"
The shafts are drilled for a close fit on the minor dia, and a snug fit on the barrel as the shaft/butt match up tight.

One more way to complicate a simple joint.

smt

One more way to complicate a simple joint, and exactly how I built a personal cue for myself long ago. A warning, G-10 pins may not work with the CF shafts. Bought a Cynergy in particular and the thread fit on the G-10 pin tightened up to the point it couldn't be turned before the the faces of the shaft and butt met. I suspect it is because the G-10 has cut threads. I had to both add a spacer and cut down my G-10 pin to get the Cynergy shaft on my cue.

Hu