Threading question

J

johnd

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When cutting threads I have been feeding with the cross slide, but want to try leaving the cross slide set on zero and feed with the compound. When doing this, should I use the compound to the full thread depth or feed in the last few thousandths with the cross slide to cut both sides of the thread? As You can probally tell, I'm very much a novice,but having a great time learning.
 
There are guys on here with a lot more experience than me, but using the cross slide at zero and feeding with the compound works for a real nice thread fit.

I really like good sharp HSS (http://www.arwarnerco.com/) for a beautiful CUT with no inclusions or burrs.

Mikes products are really, really quality stuff. IMHO, there aren't a lot of products being produced today that are worth the money, but this sure isn't the case here.
 
Being careful to square the threading tool with the axis of the thread, the compound is set at 29 degrees so that the leading edge of the tool does most of the cutting and the trailing edge makes a very light cut with each pass (in the 0.0001" range). You then feed the compound in a few thousanths with each pass. You use the cross slide to pull the tool out of the thread as you disengage the feed at the end of each pass (think walking, snapping your fingers and chewing bubble gum). As you begin the next pass you return the cross slide to zero and feed the compound a few more thousanths, ensuring that the timing dial is on the same number.
I know that on some threads (even number per inch IIRC) you can use "1" or "3" to engage, but I could never keep it straight so I just always used the same number. As you approach the finish size, your feed on the compound should be 0.001" or less.

The timing dial can be used to produce multiple lead threads, but you don't want to go there.
 
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If you are using carbide threading inserts like I do, feed straight in because the bit is at 60`. I do not want to change my set up once I start threading, changing the tool angle changes it location.
 
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"...make a 59.5* thread..." How in thwe hell can you make it 59.5* with a 60* cutter?
 
Hi JohnD,

Below is a link to a set of 5 videos that will answer your question. The insert shown costs $12.00. It has three precision ground threading cutters. It can be resharpened with a simple wet stone. No grinding involved. I made the videos just for guys like you. One really nice advantage, is that you can thread as slow as 20 rpms. and not take any chances on crashing your tooling. After you get more experience you can speed your threading up. We all have to learn some where.

http://www.youtube.com/watch?v=zoBsCrSYUhE
 
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I thread straight in, with the crossslide, using a lot of surface feet per minute, (ie, RPM), and TiN coated inserts.

I do understand that many of the machines in the hands of the hobbyist are not suited for this, but modern tooling is designed to be used in a specific manner.........jackie
 
Jackie...what RPM do you use to thread your S/S rifle barrels..???


Eddie in Texas
 
jackie...i'll bite....how do you stop the cut without some thread damage ???....i know you rethread some bbls...is thier i relief? do you thread thru the relief ?/

ahhhhhhh 350 rpm/16tpi/60 sec/min.........how much time per cut ???
you have an auto stop and just back it out ??

help

mike in co
 
You have to use the cross slide to pull the tool out of the cut as you disengage the feed. (Walk, snap fingers, bubble gum.............).
 
Thanks to all for the great input. I have ordered some Warner turning and threading tools. Gonna take muuuuch more practice before I can thread at 300 rpm though.
 
You'll get the hang of it, I've only been doing this for a couple of years with no previous machining experience and I can thread at 360 rpm. I don't do it all the time but, I can, (It sure sucks to crash a perfect shoulder) I normally thread at 70 rpm with HSS. Practice, practice, practice, and then practice picking up a thread and then practice, practice, practice; you get the picture!!

P.S.
I don't use a thread relief, I usually use my threading tool to scribe a mark where I need to stop the thread and still leave a nice shoulder for the recoil lug to ride on for a Remington since that is primarily what I work on. I've never had a problem and it makes it nice when setting back the barrel, just pick up where you left off going forward. That may not be the way the pro's do it but, it works for me.

Good Luck,
Med.
 
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I didn't know high speed threading made you a HOSS. How much time do you save on a barrel going 300 against 100rpm? I don't use a thread relief and could probably thread faster, Why?
Butch
 
Guys, I have been doing this for over 40 years, It's just something you get used to. I do not use a thread relief because I set barrels back on a regular basis.

All of the guys who say you can't get decent finishes with carbide are simply not running it at the surface feet per minute that you are supposed too.

Of course, high speeds and high surface rates means stiff set-ups, some of the older, and cheaper machines that many hobbyist and Gunsmiths use are not up to the task. I do have the luxury of having the machines in my shop at my disposal......jackie
 
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johnd said:
When cutting threads I have been feeding with the cross slide, but want to try leaving the cross slide set on zero and feed with the compound. When doing this, should I use the compound to the full thread depth or feed in the last few thousandths with the cross slide to cut both sides of the thread? As You can probally tell, I'm very much a novice,but having a great time learning.
Click to expand...

Johnd,

I see nobody Answered your questions, and were sidetracked into threading prowess.

You can clean up the thread slightly by in feeding a couple thou with the cross.

Essentially, this is what is done every pass when you leave 1/2 degree between the angle of the tool and compound.

This also gives you a slightly deeper thread when calculating back to double depth of thread.

For a clean thread grind some positive rake on the leading edge of you hss tool.

Ben
 
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