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Most common threading insert

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
Looking to get a external threading insert for a 3hp lathe. I suppose I should buy one that uses the most common size inserts on the theory they will be the cheapest to buy. I believe I am limited to 5/8" tool holders with a BXA tool post.
Bil lD.
 
As for "common", I think everybody and their brother has a system, and threading inserts are seldom dirt cheap.

I use top notches now, but honestly, they are fricken expensive. Especially J-threads, and only 2 edges per insert.
They work just fine, but expensive.

When I next need to order threading inserts, which won't be long I'm going to try the lay down style, they seem
a lot more economical. I figure a box of 10 inserts will essentially give me the holder for free, plus 10 extra edges compared
to the top notch.

EXTERNAL THREADING
 
Contact the guy with the link above.
You will be hard pressed to do any better.
(And for any interested I have no connection at all with Exkenna and he works with my enemies daily.)
Bob
 
Top notch inserts are what I use.The n3 size seems to have the most different thread forms and grooving widths and radii.I dont think that anyone makes a 5/8 toolholder that takes an n3 size. But you should find it in an n2 size.Edwin
 
Even if a BXA size quick change tool post can accept 3/4" tools, that doesn't mean you can drop the holder low enough to reach center height on many machines.

I'll agree that the better threading tool is the 16ER lay-down style. I have the "3" size Top Notch threading but much prefer the lay down style. In most cases you can get closer to a shoulder, but the bigger benefit is in using the pitch-specific inserts and you get perfect thread form.

This M20x1.5 thread made in 316 stainless steel with the insert shown, on a 1974 era Victor 1640 manual lathe.

DSC_0444-r_zps4b1358e0.jpg

DSC_0442-r_zps61146c57.jpg
 
I do notice that the cheap QC toolpost sets sold on ebay with several toolholders do not include a specific holder for threading. I guess they just go into a conventional insert toolbar.
Bill D.
 
Bill, I started with a vertical insert tool that came with my lathe and it grew into a compulsion.

For certain operations I just grind a HSS parting blade into a threader.

This is a similar tool with about 30° side rake used for fine threads and shallow cuts. It just peals ribbons of fine foil like swarf.

A R Warner has a Kit # 17 that comes with a internal/external bar and two inserts one negative and one positive. The inserts are avaliable in both Carbide and HSS. Arthur R. Warner Co. | Specialists in High Speed Steel - Kit #17R 3/8 inch Threader NV
After all this, I am transitioning into the full profile laydown inserts. These are pitch specific inserts so I am starting with things that I do more often like rifle barrell shanks. I am looking for a class three fit and nice surface finish.
You will probably get more Bang for your Buck with the A R Warner tool and not be left holding a bunch of inserts if you ultimately go another direction.
Hope this Helps!
 








 
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