First day of practice threading with lessons learned

Mram10 said:
This from tonight. Measurements were all great. +/-.001 of what I wanted. Shoulder sucks. Threads still need to be cleaner looking. Critiques please.
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Looks like you've got a bit of chatter going on. Chatter results when you set up some harmonic with flex in the system. Meaning it could be lots of things. It might be that you're taking too much material at a pass - even early on - once chatter starts subsequent passes will tend to follow it. It might be that you have the threading tool sticking out too far. (if it's poking out much, you might think about a fatter shank or a bigger holder). At this point a picture of your setup (workpiece in the chuck, tool, toolholder, tailstock support (if you're using it).

You're getting better every time.

GsT
 
Mram10 said:
This from tonight. Measurements were all great. +/-.001 of what I wanted. Shoulder sucks. Threads still need to be cleaner looking. Critiques please.
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It may be an optical illusion, but are your sure your cutter is a 60 degree vee? Something doesn't look right with the angle, maybe closer to 90?
 
Mram10 said:
Copy all guys. I don’t think my threading tool is the best. No rake on the sides, just a sharp tip. Same piece in the pics. I’ll make a new tool and try again. I’ve been using wd40 till I get some threading oil.
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You need to learn a bit about the terms and tool geometry too. That's not "rake", that's "clearance" or "relief". Rake is a different thing altogether.
 
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Once I learned how to grind my threading tool with the proper helix angle and nose flat the quality of my threads and fit improved substantialy. It might be helpful if some of those here were to share how they grind their threading tools for this gentleman.

JLouis
 
It appears that you have too much flat on your tool.

The tip width on a 60 degree thread is 10 percent of the pitch. On a 16 TPI, that's a little over .006 inch.
 
Mram10 said:
This from tonight. Measurements were all great. +/-.001 of what I wanted. Shoulder sucks. Threads still need to be cleaner looking. Critiques please.
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Mram looks like to me after reading all of the posts that you are wanting to learn how to cut and thread a rifle barrel tenon.
Do yourself a favor and get yourself some really nice cutting tools.
Warner makes some very nice HSS insert cutting and threading tools. That will help you get a good thread and cut a square shoulder the first time.. You can learn the art of grinding later.
Happy New Year Chet
 

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Can't argue with the ease of buying what you need but there is nothing like going through the frustration of learning how to grind your own and the extreme joy of it all once you finally get it all right. But I am also one who enjoys learning that of which I do not know or how to even go about what it is I might be trying to achieve while not having a clue of how to even begin. Thanks to books and help from friends and those I fully trust here I don't have to chase my tail as much I did when I first got my lathe having never turned one on prior too. I just trully enjoy the challenge of being per-say continualy self taught and the exceptional results I am now able to reap from it all that I never thought doable when first turning that lathe switch on for the first time.

JLouis
 
Threading tool

I have bought several threading tools. The one I have had the best results with is a Kennametal Top Notch holder. It is model NSR082v.
It has given me the best finish of anything I have tried.
You can get a insert with a positive cutting angle, NTP2R.
The inserts aren't cheap though. The name brand one's are around $15 ea.
You can find generic one's on the internet cheaper.
Joe Hynes
 

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Here is one of my barrel shanks. It has taken me about 6 or 7 years to get here.
There is something to learn every time I make something.
Joe Hynes
 

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liljoe said:
I have bought several threading tools. The one I have had the best results with is a Kennametal Top Notch holder. It is model NSR082v.
It has given me the best finish of anything I have tried.
You can get a insert with a positive cutting angle, NTP2R.
The inserts aren't cheap though. The name brand one's are around $15 ea.
You can find generic one's on the internet cheaper.
Joe Hynes
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That is what we use for most of the threading in our Shop. We have them that will cut up to 2 TPI in a 1 3/4 shank holder.
 
I have ordered iscar threading and cutting insert tools. Be here today. Trying to get hss to work while practicing but will try the inserts soon. After cleaning the chuck and shortening the amount of threading tool hanging out it seemed to help. The tool measures 60deg according to my fishtail. Here is one this morning
 

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Mram10 said:
I have ordered iscar threading and cutting insert tools. Be here today. Trying to get hss to work while practicing but will try the inserts soon. After cleaning the chuck and shortening the amount of threading tool hanging out it seemed to help. The tool measures 60deg according to my fishtail. Here is one this morning
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That's looking good. I'll bet the "chatter" in the first photo isn't really visible to the naked eye. I've seen where photos can really draw that out. So, next we'll work on your photography... ;-) I think you're at a point where you can cut a very usable thread and if you continue to work with your setup you'll be cutting a very high-quality thread in no time.

GsT
 
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The optimum threading tool for gun barrel steels would be positive rake, honed edge, titanium nitride(gold color) coated. Several of the well kown insert venders offer these in “top notch” design as shown by Joe Hynes, above, or in an “on-edge” (triangular) shape.

Threading any of the stainless steels, 300 series, 400 series, precipitation hardening(17-4, 18-8, etc) require special consideration since they are very low carbon content and thus very unslick. Plus atthe low surface footage we must machine them on these little tool room size lathes require much attention to detail of cutting rake and edge sharpness. Something like Joe shows above or “on-edge/triangular (TPG432-NV for example).

My best advise for amatures is to find a knowledgeable vender and consider their advis as to carbide grade, coating, and edge prep.

.

.
 
Mram10 said:
I have ordered iscar threading and cutting insert tools. Be here today. Trying to get hss to work while practicing but will try the inserts soon. After cleaning the chuck and shortening the amount of threading tool hanging out it seemed to help. The tool measures 60deg according to my fishtail. Here is one this morning
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It maybe just an anomaly that shows up in the pics but is the crest of some threads narrower than other threads?

Ian
 
Looking good what material are using to practice on.
I also noticed the miss-leading effects of the crests not looking the same probably due to the camera angle and lighting.
 
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