Pin and Thread Coverage

slyfox

slyfox

Olney Fan
Silver Member
Hello all.

Just wanted to ask about the benefits or drawbacks to more thread coverage in a pin. I understand the basic difference between the Southwest pin and a 3/8x10 or 3/8x11. I have been researching and talking to a few cue-makers to see how thread coverage affects quality of a cue.

I guess what I am asking is for instance.....

A radial pin has minimal thread coverage and contact to a shaft versus a 3/8x10 pin with deeper grooves. For example, Josey (radial) and Carolina Cues 3/18x10. I know they are both well built great cues. But is there a disadvantage to have less coverage in the thread?

I know this sounds scatterbrained but I'm having trouble describing everything the way I am perceiving it.

Thanks.
 
Basically yes. The surface area of wood thread under the pin thread. With radial pins having thinner threads than say a 3/8x10 pin, is it detrimental to the cue, shaft?

Essentially, the way I am thinking of it is that there is a more solid joint if there is more contact coverage between the pin thread and shaft thread regardless of whether the cue is flat-faced or piloted joint. If there is more surface area of wood touching the pin on the thread it should be more solid, from what I have found.

Just wondering though if there is any detriment to have less coverage of thread pin-to-wood?

I know Southwest pins have a huge amount of coverage compared to (for instance) a radial pin. In my mind this would be better and more solid for the cue. Not saying radial pins are bad.... obviously they work well for good cue makers... but is it not better to have more coverage?

Sorry if everything is redundant.... just trying to word this correctly.
Thanks.
 
slyfox said:
Basically yes. The surface area of wood thread under the pin thread. 1.With radial pins having thinner threads than say a 3/8x10 pin, is it detrimental to the cue, shaft?

Essentially, the way I am thinking of it is that there is a more solid joint if there is more contact coverage between the pin thread and shaft thread regardless of whether the cue is flat-faced or piloted joint. If there is more surface area of wood touching the pin on the thread it should be more solid, from what I have found.

Just wondering though if there is any detriment to have less coverage of thread pin-to-wood?

2.I know Southwest pins have a huge amount of coverage compared to (for instance) a radial pin. In my mind this would be better and more solid for the cue. Not saying radial pins are bad.... obviously they work well for good cue makers... but is it not better to have more coverage?

Sorry if everything is redundant.... just trying to word this correctly.
Thanks.
Click to expand...
1. Wrong. Radial has more surface contact than the regular 3/8 10.
2. How is that ? Because it has more threads ?

The radial is so tight and so straight, you can have a cue not fully jointed, and it would still roll straight.
There is absolutely nothing wrong with the radial pin . The other big pins have no advantage over it.
 
Joey,
I agree that there is no advantage or disadvantage between the two styles of pin. I guess what I am trying to get at is the actual surface area on the pin thread the the wood is under in the thread. The 3/8x10 thread sticks out farther from the pin thus allowing more surface area to be in contact between the pin thread itself, not just the pin....
I guess that what I am trying to get at. I know the radial pin is good. Josey, Klein, Reeves and a whole host of great cue makers use it.
Just wondering about the coverage under the thread itself.
Thanks for your input man. Any info is appreciated.
 
I've been building for over 20 years and repairing for 50+ years and even though they cost from 5X to 10X more money than other screws, I use Radial screws.
 
slyfox said:
Joey,
I agree that there is no advantage or disadvantage between the two styles of pin. I guess what I am trying to get at is the actual surface area on the pin thread the the wood is under in the thread. The 3/8x10 thread sticks out farther from the pin thus allowing more surface area to be in contact between the pin thread itself, not just the pin....
I guess that what I am trying to get at. I know the radial pin is good. Josey, Klein, Reeves and a whole host of great cue makers use it.
Just wondering about the coverage under the thread itself.
Thanks for your input man. Any info is appreciated.
Click to expand...
It doesn't . The regular 3/8 10 V threads lock up at the bottom of the threads with less than stellar contact in the pin's minor diameter.
The radial pin has U shaped thread. The wood's threads are shaped almost the same they have a lot more contact/mating than the regular 3/8 10.
 
Assuming proper installation, clean threads, and similar pin weights, I don't believe there is any discernible difference once the cue goes together. I don't think there is a human being on this earth that could tell what type of pin is in a cue by the way it hits, or tell the difference between them. (again assuming equal weights, and competent construction)
Sheldon <--- Radial pins, FTW
 
slyfox said:
Hello all.

Just wanted to ask about the benefits or drawbacks to more thread coverage in a pin. I understand the basic difference between the Southwest pin and a 3/8x10 or 3/8x11. I have been researching and talking to a few cue-makers to see how thread coverage affects quality of a cue.

I guess what I am asking is for instance.....

A radial pin has minimal thread coverage and contact to a shaft versus a 3/8x10 pin with deeper grooves. For example, Josey (radial) and Carolina Cues 3/18x10. I know they are both well built great cues. But is there a disadvantage to have less coverage in the thread?

I know this sounds scatterbrained but I'm having trouble describing everything the way I am perceiving it.

Thanks.
Click to expand...
I use the radial joint pin. IMO it has the most surface contact... Now Kirshenbrock would beg to differ.... He used a 3/8x11 brass joint pin in his cues and swears it has more surface contact than any other joint pin out there.. You could take his cues and screw the shaft on half way and play with it and never know it wasnt tightened all the way.. I know this for fact I have done it! Now the radial joint pin wasnt thought of at that time when he said this..
 
My feeling exactly!

Sheldon said:
Assuming proper installation, clean threads, and similar pin weights, I don't believe there is any discernible difference once the cue goes together. I don't think there is a human being on this earth that could tell what type of pin is in a cue by the way it hits, or tell the difference between them. (again assuming equal weights, and competent construction)
Sheldon <--- Radial pins, FTW
Click to expand...

Tap, tap, tap!
 
Cuemakers. . .Is the major diameter the same? If so, I think the answer to Slyfox's question is that axial contact to the thread surface is the same.

IMHO, the value in a radial pin is best stated in what JoeyinCA said, which is that the threads are contacting radially(at the minor diameter) which when screwing a shaft on an inch or so has to make the shaft basically perfectly aligned to the pin. That is the real advantage, right? All other pins rely on the joint faces being cut perfect. The radial depends on the pin being set perfect. The pin being longer and set in glue should make that easier than making the joint faces perfectly parallel, especially matching 2 shafts to 1 butt.. . . .but I don't build cues.

Did I miss something?
 
slyfox said:
Basically yes. The surface area of wood thread under the pin thread. With radial pins having thinner threads than say a 3/8x10 pin, is it detrimental to the cue, shaft?

Essentially, the way I am thinking of it is that there is a more solid joint if there is more contact coverage between the pin thread and shaft thread regardless of whether the cue is flat-faced or piloted joint. If there is more surface area of wood touching the pin on the thread it should be more solid, from what I have found.

Just wondering though if there is any detriment to have less coverage of thread pin-to-wood?

I know Southwest pins have a huge amount of coverage compared to (for instance) a radial pin. In my mind this would be better and more solid for the cue. Not saying radial pins are bad.... obviously they work well for good cue makers... but is it not better to have more coverage?

Sorry if everything is redundant.... just trying to word this correctly.
Thanks.
Click to expand...

I believe the problem that you're having visualizing this is due to the way you've learned to look at traditional 'V' threads and their perceived contact area.
The male 'V' thread makes contact with the female 'V' thread at the 'pitch-diameter'. They don't make contact at the major dia., nor at the minor dia. All 'V' threads 'locate' on the pitch-diameter. 10, 11, 12, 14 whatever, they all locate on the pitch-dia.

This is true for all 'V' threads but does not apply to the Uni-Radial.
The Radial makes contact and locates on the entire concave radius of the pin's thread. This is a totally different animal.
The 'flat-bottom' thread which is popular with the SW style 11 thd. is an attempt to achieve this in the 'V' thread but falls short in comparison.

If your quest is for more wood contact with the pin, you'd be hard-pressed to find a pin that does this better than the Radial.
 
slyfox said:
Hello all.

Just wanted to ask about the benefits or drawbacks to more thread coverage in a pin. I understand the basic difference between the Southwest pin and a 3/8x10 or 3/8x11. I have been researching and talking to a few cue-makers to see how thread coverage affects quality of a cue.

I guess what I am asking is for instance.....

A radial pin has minimal thread coverage and contact to a shaft versus a 3/8x10 pin with deeper grooves. For example, Josey (radial) and Carolina Cues 3/18x10. I know they are both well built great cues. But is there a disadvantage to have less coverage in the thread?

I know this sounds scatterbrained but I'm having trouble describing everything the way I am perceiving it.

Thanks.
Click to expand...

I have read the other responses and have nothing to add they have covered the contact issue. I will just add that the threads in as 3/8 x 10 come to an edge and as such are weaker to some degree then a radial. They will often even chip away over time and wear down. 3/8 x 10 ten's often get loose and sloppy with a lot of use. If you take everything into consideration, is one better then they other in the performance of the cue? Probably not.
Is one an more precise and dependable design for connecting a soft material (wood) to a steel screw ? Yes. I think most would agree the radial is better.
In the final analysis though, either screw far exceeds the demands that will me made of it as a cue connector.
 
nksmfamjp said:
Cuemakers. . .Is the major diameter the same? If so, I think the answer to Slyfox's question is that axial contact to the thread surface is the same.

IMHO, the value in a radial pin is best stated in what JoeyinCA said, which is that the threads are contacting radially(at the minor diameter) which when screwing a shaft on an inch or so has to make the shaft basically perfectly aligned to the pin. That is the real advantage, right? All other pins rely on the joint faces being cut perfect. The radial depends on the pin being set perfect. The pin being longer and set in glue should make that easier than making the joint faces perfectly parallel, especially matching 2 shafts to 1 butt.. . . .but I don't build cues.

Did I miss something?
Click to expand...

All cues rely on the parallel flat surfaces of the joint faces to align the shaft to the handle. The true-ness of the pin helps but is not the deciding factor. If those flat surfaces aren't parallel to one another, it doesn't matter which thread you have on the pin, the cue won't roll straight. Once those flat surfaces make full contact, they will temporarily pull even a not perfectly true pin into alignment, to a degree. However, this is creating an internal stress at the joint which will cause the cue to 'hop' at the joint when rolled on a table, as will non-parallel joint surfaces.
This can happen with a Radial pin as well. The joint surfaces will win-out.
 
Very interesting discussion

Hi,

There are many here with much more cue making experience than I and I don't want to bring up any points on the subject to make an argument but only to interject an opinion based on my observations.

To some, I may be all wet on this subject and if so I am sure that I will here about it. My thing is all about peer check and review and is the basis for my post.

First of all, considering all of the variables lets assume that a pin is inserted and epoxied into the butt with no canting of the pin and is a perfect install with no run out whatsoever.

If the drilled minor dia. is bigger than the body of the pin then the interference between the two should allow the shaft to be inserted and screwed to the butt with a very minimum resistance. Only when the facing occurs will the thread engage to lock the joint.

If the bored hole and the body of the pin are the same dia., then the pin will not work. You must have a compensation or demential gap at the minor. If you are coming to an intersection and are about to crash with another car it does not matter if you avoid the accident by 1 meter or one millimeter. Avoidance of the touching of the dia. of the hole with the body of your pin (less the thread's pitch interface) is the critical factor.

With that being said, I think that the best "Pin / Thread Coverage" occurs when the diameter of the pin is the largest possible for a piece of wood @ about .850 and the pin's threads engage with the most surface area within the shaft with a minimal differential between the hole and the pin's body. The greater the amount of thread area combined with the surface area of the face equals the most joint interface combination which is the ideal.

When we started playing with this to decided which pin would be the best for our cue's design we came to the conclusion to use a modified 3/8 x 14 tpi with a 1.750 Garolite LE insert to be threaded to recieve the pin.

Because of the fact that the wood is a fibrous matter that can weaken or break down over time, the use of an insert that is way over the tensile strength and ductility of wood seems to make the most sense. ( we have all seen the pin to wood joint that is just a small spiral in there from years of use)

Stepping the Diameter:

I have found by stepping the diameter after boring the initial hole gave me the best result. Through trial and error I have reached what I consider to be Nirvana for me in this area. We took a drill tap (see below) and had the drill section ground down to a point the where it was very difficult to screw the cue together without 2 people (4 hands) working the joint. After that we took a standard drill tap and re-tapped the shaft to a certain location point giving stepped minor dia. within the joint.

Now when the cue is put together, the threads get tighter at our stepped intersection and when the facing occurs you can't make it over tighten to stress the pitch area. Getting it just right requires a follow up with a bottom tap to an exact location to get it perfect. It took me a long time to find and be confident with the dimensions associated with that ideal location.

Rick G

Drill Tap on right has the ground drill dia.
Tap in the middle is standard
Tap on left is the bottom tap
100_1006.jpg

3/8"x14 Tpi Modifed pin with alignment barrel @ .372
P1050975.jpg
 
Last edited:
Sheldon said:
Assuming proper installation, clean threads, and similar pin weights, I don't believe there is any discernible difference once the cue goes together. I don't think there is a human being on this earth that could tell what type of pin is in a cue by the way it hits, or tell the difference between them. (again assuming equal weights, and competent construction)
Sheldon <--- Radial pins, FTW
Click to expand...

I agree. Here's an interesting read.
http://groups.google.com/group/rec.sport.billiard/msg/0dd0fbb3be509b85?dmode=
 
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