Pin Threads?
- Thread starter cuedaddy
- Start date
I used to be a machinist and i used to make machine threads all the time, and i believe other than the 5/16 14 joss pin and the 18 there isn't much info on other threads. There are formula's for figuring out all the proper dimensions of any thread meaning you could technically make a 2 in pin with a 36 pitch thread on it why idk. But most pins are not common threads get your self a copy of the machinist hand book and it will have everything you need to do anything you want with threading. I think cue makers did this to distinguish their product from knock offs. imo
> For pins that fall under the category of 60 degree V-groove,you divide
.6495 by your number of threads per inch.
Example,you have machined a steel rod to .375 for a true 3/8 or MAJOR diameter. You want to cut the screw at 12 TPI.
.6495 divided by 12 =.054125 or .054. This number represents your SINGLE depth of thread for that screw. Multiply that number x 2,and that number gives you the correct number of your MINOR diameter.
So,.054 x 2 = .108.
.375 (maj) -.108=.267 (min)
Now remember to make sure if you're doing this on a manual lathe,that all your travel should come from the compound,which should be set at VERY close to 30 degrees. I tend to set it and leave it at 29.5,so it takes a slight cleanup cut on the backside of the threads.
Another useful formula is .708 divided by the desired number of threads. This calculation gives you the INFEED,or how far the compound should be dialed in to get you to the desired thread but this is not exact unless you have a nice,tight lathe,as well as complete control over your tool touch-off pressure.
This number can vary by as much as .010 on such a thing.
In this case,.708 divided by 12 =.059. This means that after you touch the tool off and reset your wheels (or readout),you SHOULD be very close when the wheel on the compound says you have dialed in .059-.060.
Sorry if this seems like a complicated explanation,because it's not really. Five minutes with me in front of a manual lathe that doesn't have all metric controls and I promise you'll never forget how to calculate this.
By the way,there are some thread ranges,such as the Radial (7.637 I think),and odd stuff like 11.5 that you might not have a setting for.
Hope this helps,Tommy D.
.6495 by your number of threads per inch.
Example,you have machined a steel rod to .375 for a true 3/8 or MAJOR diameter. You want to cut the screw at 12 TPI.
.6495 divided by 12 =.054125 or .054. This number represents your SINGLE depth of thread for that screw. Multiply that number x 2,and that number gives you the correct number of your MINOR diameter.
So,.054 x 2 = .108.
.375 (maj) -.108=.267 (min)
Now remember to make sure if you're doing this on a manual lathe,that all your travel should come from the compound,which should be set at VERY close to 30 degrees. I tend to set it and leave it at 29.5,so it takes a slight cleanup cut on the backside of the threads.
Another useful formula is .708 divided by the desired number of threads. This calculation gives you the INFEED,or how far the compound should be dialed in to get you to the desired thread but this is not exact unless you have a nice,tight lathe,as well as complete control over your tool touch-off pressure.
This number can vary by as much as .010 on such a thing.
In this case,.708 divided by 12 =.059. This means that after you touch the tool off and reset your wheels (or readout),you SHOULD be very close when the wheel on the compound says you have dialed in .059-.060.
Sorry if this seems like a complicated explanation,because it's not really. Five minutes with me in front of a manual lathe that doesn't have all metric controls and I promise you'll never forget how to calculate this.
By the way,there are some thread ranges,such as the Radial (7.637 I think),and odd stuff like 11.5 that you might not have a setting for.
Hope this helps,Tommy D.
cuedaddy
Banned
I Printed this off!
Thank you for the info..
Ill just run throught it so im sure I have an understanding
I want a 3/8x10tpi pin..
So I turn the given piece to a little over 3/8
Ill create a smaller diameter section near the left side where the cutter will stop.
the minor diameter for 10tpi will be .0649 x 2 smaller than the major diameter or .12" from the major diameter of .375 = .255
.375 = Major Diameter (Largest)
.255 = Minor Diameter (Smallest)
So I zero the dial on the piece with the compound at 30deg off from center.. or is it the angle of the tool that we are talking about?
so Turn Turn Turn.. down to the point that the dial reads out to .225 or back to .0649 from zero.. or a tad lighter for further cleanup
Corect me if im wrong..
AND THANK YOU!!