5/16-18 joint mystery.

straightline said:
Wonder if Dr. Dave has any opinions on this.
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Any machinist can make up any thread from the top of his head and it will pull things together. He could make it with oval shaped threads. Would probably work fine for a cue as well. That’s how it was in the beginning. Standards came into place to allow inter-operability.

We’ll probably see more metric threads in the future is my guess, as the popularity of aliexpress cues increases.
 
Michael Webb said:
It's been my mission aka nightmare learning about the different joint screws for 30 years. I still don't know them all and new one's are still coming.
Another new one that looks like the 5/16x18 is M8x1.25.
It's out there and looks very similar to Pechauer's quick release.
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It's enuf to make a cuemaker want to join the foreign legion!!🤣
 
Cornerman said:
I was talking about a piloted nose on the joint thread not the pilot of the shaft insert into the butt. I think you’ve got confusion going on. The Schon is an undersized 5/16-14. That means the shaft thread is too small on the diameters vs the Joss and others.

if Bill Stroud actually was trying to put a true acme thread on a cue joint, I think he wasn’t thinking things through.. Bill was a great cue guy, and a pioneer. But he was no mechanical engineer. You can take that to the bank.
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I've been dazed and confused since Christ left Chicago my friend!!
 
Ac
3kushn said:
The OP derailed his own thread talking about other thread forms than a basic 60deg 5/16"-18 thread.
Cueman offered him the answer. I tried to offer ANSI Specs/Limits in support of Cueman, then he's talking about Acme and other thd forms.

Maybe the goal is 100 responses.
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No goal here, just when I started I was clueless and looking for all the info I could get. Little did I know it was going to run thru the jungle. Lol.
It's like Chinese arithmetic or aiming systems. 🤣 The minute variances that don't at first glance seem to add benefit, may or may not, depending on issues I now understand thanks to the kind, informative members of AZ!!!
 
3kushn said:
The OP derailed his own thread talking about other thread forms than a basic 60deg 5/16"-18 thread.
Cueman offered him the answer. I tried to offer ANSI Specs/Limits in support of Cueman, then he's talking about Acme and other thd forms.

Maybe the goal is 100 responses.
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Shore nuff didn't mean to. 😁
 
iusedtoberich said:
I found one on a search:) Check out the joint picture it shows the acme thread.

FS: Tim Scruggs Custom 4 Point Pool Cue Ebony, Ivory 2 Shafts

I will be listing some cues for sale in the next few weeks. I'm selling off a collection for someone in my area. The first one is a Tim Scruggs custom cue built in the year 2000. The cue has four veneered points with Ivory and what looks like turquoise inlays. Other cues to be listed...
forums.azbilliards.com
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Don't wanna get to far off topic here, but since Tim's name came up, his 13mm shafts almost to the piece, weighed 4 ozs or better. Is this standard thru the industry?? Or did it have more to do with the wood back then. The heavy, tight grained, old growth maple?? Just curious. Mike?? Garczar??
 
cueman said:
You asked the same questions over in the cuemakers forum and here is the answers I posted there for the benefit of those on the main forum.

The thread angle on all mentioned is 60 degree. But the outside diameter varies. Thus Huebler shaft goes on Meucci, but Meucci does not go on Huebler. Common 5/16-18 outside diameter is .310" only two thousandths undersized to true 5/16. But Meucci is often closer to .300" and .304' or so its very common also. Also sometimes the threads are not rolled as deep which makes them fit tighter. Some use a 17/64 (.266") hole in the insert before tapping or threading and others use an F drill (.256") and others use a 1/4 (.250"). So yes thousandths matter and the combination of factors matter. The .300" john screw will go in any of the above tapped inserts, but only the .300" pin will go in the insert tapped into the .250 hole. I wont even go into H factor taps since most use CNC lathes to cut threads now instead of tapping brass parts. But they still use factors to decide how tight the fit is.
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Unreal!!!
 
cueman said:
You asked the same questions over in the cuemakers forum and here is the answers I posted there for the benefit of those on the main forum.

The thread angle on all mentioned is 60 degree. But the outside diameter varies. Thus Huebler shaft goes on Meucci, but Meucci does not go on Huebler. Common 5/16-18 outside diameter is .310" only two thousandths undersized to true 5/16. But Meucci is often closer to .300" and .304' or so its very common also. Also sometimes the threads are not rolled as deep which makes them fit tighter. Some use a 17/64 (.266") hole in the insert before tapping or threading and others use an F drill (.256") and others use a 1/4 (.250"). So yes thousandths matter and the combination of factors matter. The .300" john screw will go in any of the above tapped inserts, but only the .300" pin will go in the insert tapped into the .250 hole. I wont even go into H factor taps since most use CNC lathes to cut threads now instead of tapping brass parts. But they still use factors to decide how tight the fit is.
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This subject seems to come up quite a bit in places I play and I don't like to comment on things when I'm not certain wtf I'm talking about. Noone sems to know and there's a lot of speculation and general guessing goin on and I wanted to hear what the experts here had to say, so the next time this comes up, I can actually tell some guy why that shaft won't fit that butt in a more technical way than "just cuz it won't!!"🤣
 
Mensabum said:
This subject seems to come up quite a bit in places I play and I don't like to comment on things when I'm not certain wtf I'm talking about. Noone sems to know and there's a lot of speculation and general guessing goin on and I wanted to hear what the experts here had to say, so the next time this comes up, I can actually tell some guy why that shaft won't fit that butt in a more technical way than "just cuz it won't!!"🤣
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The funny thing about that...

...in industry, probably better than 99% of all threads that are inspected are checked with a go-no go gauge, which tells the inspector, that the thread just doesn't fit. It would then be up to the manufacturer/machinist to determine why it doesn't fit.
 
DeeDeeCues said:
The funny thing about that...

...in industry, probably better than 99% of all threads that are inspected are checked with a go-no go gauge, which tells the inspector, that the thread just doesn't fit. It would then be up to the manufacturer/machinist to determine why it doesn't fit.
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Either or, then send back?? Wow. Seems like a lot of blowback on that poor bastard. They need a monkey middleman to free up the machinist. Can't pay a guy enuf to deal w all that bullshit.
 
Mensabum said:
Either or, then send back?? Wow. Seems like a lot of blowback on that poor bastard. They need a monkey middleman to free up the machinist. Can't pay a guy enuf to deal w all that bullshit.
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That all depends on a lot of factors. If it was a single machinist making the screw (doubtful, most are rolled or formed), then it is on him to make a part to spec and there would be a record on how many parts he didn't make to spec, eventually leading to promotions, demotions, firing, etc..

In the case of screws, they are likely formed and not machined. The internal QA department would hopefully catch parts before they leave and fix whatever problems arise.

In the case of very high tolerance screws, it is a bit different. I know a decent amount about Bosch Rexroth rolled ballscrews, so I'll use that as an example. When BR makes a run of rolled ball screws, they will run the whole batch and inspect after. They then sell these screws in different precision grades at vastly different costs. They do this because the difference between the highest and lowest grades is pretty small, and there are so many factors that can change, causing enough variance to move a screw from one class to another. They basically always try to create the most precise grade of screw, but they know that only a small percentage are going to meet the classification. Many others will be slightly lower, others lower still, and a few will fail altogether.

Ground ballscrews and rollerscrews are a completely different story...and the price reflects it.
 
Mensabum said:
Don't wanna get to far off topic here, but since Tim's name came up, his 13mm shafts almost to the piece, weighed 4 ozs or better. Is this standard thru the industry?? Or did it have more to do with the wood back then. The heavy, tight grained, old growth maple?? Just curious. Mike?? Garczar??
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I'm outta this. FAR smarter people on this subject have pretty much cleared it up.
 
Mensabum said:
I've seen two Joss West w acme pins.
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Yes, JW used a 5/16x14 acme in some of his Cue.
I provided pictures earlier but will again. The acme screw on the right side is an actual JW joint screw. But the funny part is, some JW Cues have a thinner 5/16x14 acme around the actual 5/16" size as compared to the .323 acme.
Tim Scruggs used a 3/8x10 acme in some of his Cues.
Mike Gulyassy still offers 3/8x10 acme joint screws in his Cues.
 

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Mensabum said:
Knowing what I know now, this can of worms would have remained unopened. 😉
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Open the can
Tear the lid off. This is good stuff.
The answer when it comes to Joint screws is.....
They vary in size. Most of the screws are rolled thread, some are single pointed.
Roll thread, depends on what company produced them and the size dies they used.
Single pointed can vary too. Check previous discussions on the Radial joint screw. They vary!
 
Have
DeeDeeCues said:
That all depends on a lot of factors. If it was a single machinist making the screw (doubtful, most are rolled or formed), then it is on him to make a part to spec and there would be a record on how many parts he didn't make to spec, eventually leading to promotions, demotions, firing, etc..

In the case of screws, they are likely formed and not machined. The internal QA department would hopefully catch parts before they leave and fix whatever problems arise.

In the case of very high tolerance screws, it is a bit different. I know a decent amount about Bosch Rexroth rolled ballscrews, so I'll use that as an example. When BR makes a run of rolled ball screws, they will run the whole batch and inspect after. They then sell these screws in different precision grades at vastly different costs. They do this because the difference between the highest and lowest grades is pretty small, and there are so many factors that can change, causing enough variance to move a screw from one class to another. They basically always try to create the most precise grade of screw, but they know that only a small percentage are going to meet the classification. Many others will be slightly lower, others lower still, and a few will fail altogether.

Ground ballscrews and rollerscrews are a completely different story...and the price reflects it.
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Have the tolerances on those lessened over the years?? I've heard the Japanese have the tightest, most rigid tolerances in the world.
Have we gotten lazy and missed a step or two??
Or is that just heresay??
 
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