Adjustable Die for Tenon??

M

Mram10

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I got to thinking about it (here is where trouble always begins) and why not thread your tenon to within .005” of finished measurement then use an adjustable die to verify they are the exact same every time? The die can be adjusted for whatever fit you like on the action.
 
Mram10 said:
I got to thinking about it (here is where trouble always begins) and why not thread your tenon to within .005” of finished measurement then use an adjustable die to verify they are the exact same every time? The die can be adjusted for whatever fit you like on the action.
Click to expand...

Not a good idea! A while back a fellow brought a rem 700 into the shop for some work. It turned out to be another one for the books! When I took the barrel off things didn't look quite right sooo I took a few measurement. Instead of the O.D. being 1.062 it was 1.032 which explained the flats on top of the threads. As near as I can figure someone tried to run a 1 1/6 die an found out it required more torque than he was able to generate or wasn't able to keep the barrel from slipping in the chuck. With the smaller dia. he did get it threaded. This left around .016 thread engagement which apparently worked. If he'd of used a rigid pipe threading machine that would have worked accept for the jaw marks that would have been left on the barrel. ALSO the threads would not be concentric and square with the shoulder. I guess this illustrates how little thread engagement is required to keep a barrel in a receiver. As I said earlier "not a good idea".
 
Your example is very different. If it is adjustable, you can make it 1.062” od and just clean up the last .005” of the threads. How would that not be a good idea?
 
Mram10 said:
I got to thinking about it (here is where trouble always begins) and why not thread your tenon to within .005” of finished measurement then use an adjustable die to verify they are the exact same every time? The die can be adjusted for whatever fit you like on the action.
Click to expand...

Mram,
I think you will find it easier to make them "exactly the same" with a proper threading tool and either wires or a thread mic (my preference) to verify correct pitch.
I keep a record of the proper pitch for all actions I work on as some are not as consistent as others.
As I and others more knowledgeable then me have commented often in the past loose is better then tight. How loose is up to you:)
You can find the proper tolerances (+/-) for the different classes of fit in the threading section of Machinery Handbook
Just my opinion, worth what I charge for it.
Regards,
Greg
 
Wf,
I’ve always threaded with a carbide insert rh tool and custom fit for each action. After making a short action for switching barrels, it made sense that all will be the same size and a die could make that happen easily. Sure, 2 more passes and another cleanup would take the same or less time. Just curious if anyone has tried it.
 
Mram10 said:
Your example is very different. If it is adjustable, you can make it 1.062” od and just clean up the last .005” of the threads. How would that not be a good idea?
Click to expand...

I misunderstood you. I thought you were talking about cutting the entire thread with a die. Sorry about the misunderstanding.
 
Just from a machinist point of view, I would think you cut keep threads more identical and with a better finish with the tried and true measuring techniques that accurately measure the pitch diameter.
 
jackie schmidt said:
Just from a machinist point of view, I would think you cut keep threads more identical and with a better finish with the tried and true measuring techniques that accurately measure the pitch diameter.
Click to expand...

Single point threading can easily produce threads better than just about any die.

You would need a relatively complicated setup to hold a die and make sure
it stayed perfectly perpendicular to the thread axis.

Like trying to use it as a cutter on a rigid lathe setup.

And there are lathe cutters with multiple 'teeth' for screws.
Often larger screws.
They are more suitable to a production environment.
 
I _think_ What Mram10 is saying is that he thinks a die could be used to "clean up" his threads after single-pointing to within .005 of finished dimension........and that he feels this will result in "more repeatable accuracy"
 
The die will clean up any burrs, etc. But it has to be started straight. If anything use the die without the handles to basically check the threads like using a gage. Better would be to get a set of thread ring gages to check your work as it progresses. Get a plus size and an exact size and an under size. When the plus screws on, you know that a few thousands more off will make the exact gage fit, if the under fits then too small, . All tenons would then be within tolerance. Just practice on scrap until it becomes easy.
 
I had someone give me some used barrels that were threaded for a Panda. I have an early Viper that takes a tenon with a slightly smaller pitch diameter, but which is identical to the Panda's in all other respects. In order to be able to try one of the barrels I shopped around and found an adjustable die of the correct diameter and thread pitch. In the process of working with that die, using the pitch diameter of one of my barrels as a reference, I ran into an unexpected issue. The female thread in my action's insert (aluminum action body, steel insert) do not come to a sharp V. The die produces threads that do. When I had the three wire measurement of the barrel that I was given so that it should have fit the action, it did not. I had to adjust the die to produce a smaller pitch diameter to make it work, so much so that I ran out of die adjustment (Remember that the die adjustment spreads the die to produce a progressively larger pitch diameter.) leaving me the retaining screw in the die stock to further close up the die. This is a very imprecise process. For that matter so was the adjustment of the die, all cut and measure. When I finished I had a thread fit that was much much looser than I wanted, so much so that I measured the tenon and calculated the amount of thread overlap to make sure that it was safe. It was. The barrel came to a hard stop when I tightened it on the action, and there were no problems when I fired my usual loads. The funny part is that that barrel is one of my most accurate, sloppy fit and all, but I will leave my speculation as to why that is for another discussion.
 
i do not know for a fact in this case,
but most threaded inserts are finished with a roll form tap.

Boyd Allen said:
I had someone give me some used barrels that were threaded for a Panda. I have an early Viper that takes a tenon with a slightly smaller pitch diameter, but which is identical to the Panda's in all other respects. In order to be able to try one of the barrels I shopped around and found an adjustable die of the correct diameter and thread pitch. In the process of working with that die, using the pitch diameter of one of my barrels as a reference, I ran into an unexpected issue. The female thread in my action's insert (aluminum action body, steel insert) do not come to a sharp V. The die produces threads that do. When I had the three wire measurement of the barrel that I was given so that it should have fit the action, it did not. I had to adjust the die to produce a smaller pitch diameter to make it work, so much so that I ran out of die adjustment (Remember that the die adjustment spreads the die to produce a progressively larger pitch diameter.) leaving me the retaining screw in the die stock to further close up the die. This is a very imprecise process. For that matter so was the adjustment of the die, all cut and measure. When I finished I had a thread fit that was much much looser than I wanted, so much so that I measured the tenon and calculated the amount of thread overlap to make sure that it was safe. It was. The barrel came to a hard stop when I tightened it on the action, and there were no problems when I fired my usual loads. The funny part is that that barrel is one of my most accurate, sloppy fit and all, but I will leave my speculation as to why that is for another discussion.
Click to expand...
 
Boyd Allen said:
I had someone give me some used barrels that were threaded for a Panda. I have an early Viper that takes a tenon with a slightly smaller pitch diameter, but which is identical to the Panda's in all other respects. In order to be able to try one of the barrels I shopped around and found an adjustable die of the correct diameter and thread pitch. In the process of working with that die, using the pitch diameter of one of my barrels as a reference, I ran into an unexpected issue. The female thread in my action's insert (aluminum action body, steel insert) do not come to a sharp V. The die produces threads that do. When I had the three wire measurement of the barrel that I was given so that it should have fit the action, it did not. I had to adjust the die to produce a smaller pitch diameter to make it work, so much so that I ran out of die adjustment (Remember that the die adjustment spreads the die to produce a progressively larger pitch diameter.) leaving me the retaining screw in the die stock to further close up the die. This is a very imprecise process. For that matter so was the adjustment of the die, all cut and measure. When I finished I had a thread fit that was much much looser than I wanted, so much so that I measured the tenon and calculated the amount of thread overlap to make sure that it was safe. It was. The barrel came to a hard stop when I tightened it on the action, and there were no problems when I fired my usual loads. The funny part is that that barrel is one of my most accurate, sloppy fit and all, but I will leave my speculation as to why that is for another discussion.
Click to expand...


seee now I woulda' done different Boyd :)

I'da' run that sum'buck up ag'inst the belt sander and spun 'er down some.....
 
jackie schmidt said:
Just from a machinist point of view, I would think you cut keep threads more identical and with a better finish with the tried and true measuring techniques that accurately measure the pitch diameter.
Click to expand...

Jackie,
Thats what I was trying to get across in my earlier post.
Glad to have someone who knows what they're talking about weigh in.:rolleyes:

Dies are for pipe fitting not barrel threading.

One mans opinion worth what I charge.
Greg
 
alinwa said:
I _think_ What Mram10 is saying is that he thinks a die could be used to "clean up" his threads after single-pointing to within .005 of finished dimension........and that he feels this will result in "more repeatable accuracy"
Click to expand...

Exactly, Sir
 
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