# Threading Up To A Flange



## terry_g (Mar 15, 2021)

There is no gunsmithing forum here so I will post this here as it has other applications.
I made a cat-head to thread into the outboard end of the lathe spindle. I think that is the correct terminology
I also made a crank handle that fits over the cat-head.
I needed to cut threads on a rifle barrel the stop at a flange.
Make sure the lathe head-stock is out of gear and the breaker is off.


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## DPittman (Mar 15, 2021)

Nice job. How did the threading go?


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## terry_g (Mar 15, 2021)

Actually it turned out with a nice finish. I still have some now banned toxic thread cutting fluid.


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## DPittman (Mar 15, 2021)

terry_g said:


> Actually it turned out with a nice finish. I still have some now banned toxic thread cutting fluid.


Do you use hss or carbide for threading?  I think hss gives a nicer thread finish when turning slow by hand.  I think it's because you can such a sharp edge on it.
What's "banned" cutting fluid?  Now I want some!


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## terry_g (Mar 15, 2021)

I use HSS for slow cutting finish sharpened with a diamond file.
The cutting paste was from 40 years ago the label from the can is long gone.
When I found out in the mid 1980s it was no longer available I bought the last 2 cans the supplier had.


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## Swharfin' (Mar 15, 2021)

You have my interest. SS or 4140? 1.062" x 16 or 0.010" over?


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## 6.5 Fan (Mar 15, 2021)

If possible i cut a relief groove on the barrel shank just before the barrel flange. Have seen a couple threads cut by hand but never needed to myself with the relief groove. What are you installing it on and what chamber?


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## Swharfin' (Mar 15, 2021)

Ha! here we go the dams leaking.


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## terry_g (Mar 15, 2021)

The last one I did lost accuracy because of throat erosion. It was a .223 Savage 12FV.
A small shank savage is 1.050" x 20 TPI if I remember correctly. It was 4140 not SS
I machined .200" off the breech end of the barrel and cut the chamber .180" deeper with a chamber reamer.
and cut '200 more thread on the barrel. A Savage barrel is retained with a lock nut.
It took a few tries but I got it clocked the same so the markings on the barrel were where they started
and I lost one proof stamp or you would never know I tampered with it.
It was once again very accurate.

Also a very nice rifle with a Boyd's thumb-hole!!


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## 6.5 Fan (Mar 15, 2021)

Yes the Savage are much easier to set back, the barrel nut makes things much easier. Looks like a lot of companies are going that route. Nice looking rig.


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## DPittman (Mar 15, 2021)

Do you ever turn the threading tool upside down and start the thread at the shoulder and move towards the tailstock ( under power)?


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## Swharfin' (Mar 16, 2021)

Fine looking piece I like Boyds stocks I think they're very underrated. Wood feels better on the cheek @ -20C than glass or synthetic.


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## historicalarms (Mar 16, 2021)

Thats the very first piece I built & threaded with my lathe to steady the outboard end of barrels in the headstock...and then was taught that barrel chambering & threading set-up is easier done with a steady rest. 
     I also added a handle and crank for the same reason you did and it gets used more for that than steadying a long shaft. 
    I have read of the "reverse threading " being used for barrel tenons & threads but have never done it, It is feasible from a "start to finish new thread's point of view I think but in my case , it would create a disaster. 
     In my case  (and the OP's I think) I am just adding a thread or two to an already threaded tenon so meshing with the old thread pitch is essential in the beginning. You have to start in the old thread and cut too the new barrel buttress... someone very experienced could probably manage this "under power" but for an armature, "slow & precise" is the cheapest method....errors cost 4-$600 in a heartbeat.


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## Swharfin' (Mar 17, 2021)

Same here   4-5 wk.'s time to replace a custom barrel. 
Can somebody enlighten us on the rear tool post method ?


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## 6.5 Fan (Mar 18, 2021)

Never used a rear tool post but saw a video on it. A few lathes have a set up for it otherwise you need to Macgiver a holder on the cross slide to get your tool bit on the wrong side of the work and run in reverse, which doesn't work for a threaded on chuck for obvious reasons though. I have enough trouble sometimes with the regular tool holders so going opposite holds no appeal to me.


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