# DIE  HOLDER VS SINGLE CUT



## riversidedan (May 13, 2021)

BEEN USING A GRIZZLY 4X6 AS A LEARNING TOOL AND HAVING FUN MAKING PARTS AND $$$$  TOO BUT the time will come when Ill  need a BIGGER LATHE WHICH IS ON THE HORIZON. AND COMING SOON..........BEEN SEEING SOME INFO ON YOUTUBE RE DIE HOLDERS VS. SINGLE CUT THREADING  AND LIKE THE DIE HOLDER IDEA WAY BETTER WHICH SEEMS less complicated AND DOES THE SAME JOB, SO WHEN I GET MY NEW 7x14 WILL SEE HOW IT GOES.......I didnt pay too much for the 3 die set and really dont plan to use  it that much,  but its thier if the time comes.


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## Aukai (May 13, 2021)

Single point will take less power to thread, the die holder you will probably hold, and turn by hand. I think....


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## redgrouse (May 13, 2021)

*It depends on what you mean by die holders?  Round split dies or a die box (Coventry die box) for production work.  Also depends on what you are making and the accuracy of the thread required etc etc
Split dies are economical and give reasonable result for general work
Coventry dies or similar give a high quality thread much better accuracy and a higher productivity rate, much more expensive as well.*


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## machPete99 (May 13, 2021)

Single pointed threads are likely to be more concentric than using hand dies, even with a tailstock holder.
You can always do most of it single point and finish up with a dies stock which works pretty good.


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## Aaron_W (May 13, 2021)

It depends on the accuracy required, single point can be more precise. Tailstock die holders or even just using the tailstock to support and line up a conventional T handle die holder works for many small parts. 

Personally I find using a tap or die easier than single point, but that is because to single point I usually have to use change gears or have to set up a threading accessory (Sherline). 

If you looking at a mini-lathe you will be in the same situation. Single point threading is easier when a Quick Change Gear Box is available, but you don't find that on many lathes under 9-10".


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## Shootymacshootface (May 13, 2021)

Why are you guys yelling?


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## Winegrower (May 13, 2021)

While a Geometric die head is not suitable for the little lathes discussed here, for 10" plus lathes, they are much faster and easier than either single point threading or running a die.   If  you have to do much of this, it's worth looking into.   Each unique thread pitch can be purchased for maybe $10 or so on eBay.    I paid $150 for my die head with 4 thread pitches.


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## Aaron_W (May 13, 2021)

Winegrower said:


> While a Geometric die head is not suitable for the little lathes discussed here, for 10" plus lathes, they are much faster and easier than either single point threading or running a die.   If  you have to do much of this, it's worth looking into.   Each unique thread pitch can be purchased for maybe $10 or so on eBay.    I paid $150 for my die head with 4 thread pitches.
> 
> View attachment 365752



I see these pop up on CL once in a while. Are these usually used with a 3 or 4 jaw chuck? Most seem to just have a straight shank, I don't usually see them with a common mounting system like a chuck would use or a tapered shank to be held in the spindle with a drawbar.


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## benmychree (May 13, 2021)

Automatic die heads such as the Geometric are available as small as 5/16" capacity, but they are not cheap by any means, neither are the chaser sets.  I do not think they would be suitable for lathes smaller than 9" swing, as they do not possess much torque capability.  Thread quality will nearly always be better with single pointing so far as true pitch and thread wobble is concerned, which happens all too often with button dies.


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## benmychree (May 13, 2021)

Aaron_W said:


> I see these pop up on CL once in a while. Are these usually used with a 3 or 4 jaw chuck? Most seem to just have a straight shank, I don't usually see them with a common mounting system like a chuck would use or a tapered shank to be held in the spindle with a drawbar.


No, they were designed to (mostly) be held in the hex turret of a turret lathe, but adaptors can be made to fit them on the OD of the tailstock quill, or they can be held in a boring bar holder of a QCTP.  Automatic dies are also rotated in a headstock of powered threading machines where the die rotate and the work is held stationary in a sliding vise and fed into the die head.


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## Aaron_W (May 13, 2021)

benmychree said:


> No, they were designed to (mostly) be held in the hex turret of a turret lathe, but adaptors can be made to fit them on the OD of the tailstock quill, or they can be held in a boring bar holder of a QCTP.  Automatic dies are also rotated in a headstock of powered threading machines where the die rotate and the work is held stationary in a sliding vise and fed into the die head.



These are big and "chuck like" so that just made me think chuck, but lathe turret makes a lot of sense, as it seems most die holders are made to be used in the tail stock.


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## benmychree (May 13, 2021)

Yes, they can be quite large, we used one at Kaiser to thread 2 1/4" rebar with 4 1/2 pitch, right over the ribs, done in several (maybe 3 passes), the threading was done undersize and they were hot dip galvanized after being welded into cages for electrical transmission tower foundations.  The die head was about 10 inches in diameter, made by Landis, with tangent chasers; the beauty of this die was that if chasers broke (and they did), you could take a chaser of the same number, of any length and substitute it for the broken one, and all chasers were sharpened without regard to length, as with other tangent die heads like the J&L, where chasers had to be sharpened to an accurate length, measured with special fixtures; with care, Landis chasers could be sharpened on an ordinary bench grinder, I've been told, and most any diameter could be threaded within the range of the die, with any pitch of chaser.
So endeth my die head rant!


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## macardoso (May 13, 2021)

Winegrower said:


> While a Geometric die head is not suitable for the little lathes discussed here, for 10" plus lathes, they are much faster and easier than either single point threading or running a die.   If  you have to do much of this, it's worth looking into.   Each unique thread pitch can be purchased for maybe $10 or so on eBay.    I paid $150 for my die head with 4 thread pitches.
> 
> View attachment 365752


If I wanted to buy one, what would I search for? I have a 12x36 lathe with an MT2 tailstock.


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## mmcmdl (May 13, 2021)

They are out there . I know where a couple reside at this point . Better to run them in your carriage though as you can thread thru the die head for long threads such as all thread .


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## mmcmdl (May 13, 2021)

macardoso said:


> If I wanted to buy one, what would I search for? I have a 12x36 lathe with an MT2 tailstock.


I have Geometric die heads in 3/8s and 3/4s sizes as well as the chasers . As time allows , they'll be listed below . I also have the chaser grinding fixture for sharpening them if anyone has a SG .


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## benmychree (May 13, 2021)

For a 9 or 10" lathe, I'd look for a Geometric 9/16 style D die head.  There are other brands out there, but Geometric is the most common and easy to set up and change chasers, which are also more plentiful.  I also use a Jones & Lampson Hartness die head, it is a PITA to change chasers, but it came cheap, with lots of chasers.


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## macardoso (May 13, 2021)

mmcmdl said:


> I have Geometric die heads in 3/8s and 3/4s sizes as well as the chasers . As time allows , they'll be listed below . I also have the chaser grinding fixture for sharpening them if anyone has a SG .


I'll be watching


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## mmcmdl (May 13, 2021)

After getting them out , I have a 9/16s and 3/4 . I used the smaller one more on the mill than the lathe . Set up a Hardinge head with stop and you can knock some threads out in a hurry


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## benmychree (May 13, 2021)

So far as I know, Geometric die heads came in 5/16, 9/16, 3/4, 1", and 1 1/4" sizes and perhaps larger, and in several styles, including style D, the most common, and the easiest to get chasers for.  The others, including DS, not too easy to get reasonably priced chasers for.


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## Winegrower (May 13, 2021)

benmychree said:


> For a 9 or 10" lathe, I'd look for a Geometric 9/16 style D die head.


This is the size I have.   I have chasers from 4-40 up to 1/2-13.   I just hold the straight shank in my tailstock Jacobs chuck, that opens to 3/4”.   I can change to a different thread pitch in maybe a minute, after I remember afresh how to do it each time.   
The thread quality for me is at least as good as single point, and I tell you, zap, it’s done.    I would and have set this up to do a single part.


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## benmychree (May 13, 2021)

I just did a search to find my Geometric die brochure describing all the different types, but of course stuck out, but my advice would be, consider ONLY the style D die head.


Winegrower said:


> This is the size I have.   I have chasers from 4-40 up to 1/2-13.   I just hold the straight shank in my tailstock Jacobs chuck, that opens to 3/4”.   I can change to a different thread pitch in maybe a minute, after I remember afresh how to do it each time.
> The thread quality for me is at least as good as single point, and I tell you, zap, it’s done.    I would and have set this up to do a single part.


All true and good advice.  I made a sleeve that fit my 9/16 die head that slipped over the tailstock quill, that had a key to engage the keyway in the quill and a setscrew to keep it from sliding off.  I would set the carriage in position to limit tailstock travel for the length of threads wanted; the tailstock would run into the carriage and the die would trip and open up.  Later I adopted the Aloris boring tool holder with 1 1/2" hole and mounted the die head in it and used the carriage stop to trip the die.  I have tried using the lead screw to power the travel of the die head, but generally, this does not seem to work, as it seems that deviations in the pitch diameter (of the part being threaded) effect the lead of the screw being cut, and generally with a long cut, the die will pull itself off (trip) before the desired length is reached, so the lead of the thread would be longer than expected, this with undersize pitch diameters.


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## benmychree (May 13, 2021)

I don't like the idea of holding tools other than centers in the taper of the tailstock quill for jobs such as heavy drilling, etc, this is how the tapers get buggered up, resulting in inaccuracy.  One exception would be for tailstocks quills that incorporate a tang slot, such as on American Pacemaker lathes.


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## Winegrower (May 13, 2021)

benmychree said:


> I have tried using the lead screw to power the travel of the die head, but generally, this does not seem to work,


Huh, never thought of that.  That would imply a big mismatch between lathe tpi setting and chaser tpi, no?


benmychree said:


> One exception would be for tailstocks quills that incorporate a tang slot, such as on American Pacemaker lathes.



Agree, the Takisawa has a tailstock tang slot and all the MT3 accessories have a tang.


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## benmychree (May 13, 2021)

In the above I stated that the die head would often pull off when attempting to use the lead screw to follow it up; If the lathe is set up for the same TPI pitch of the chasers, one would think that it should work, but on a die head, if the die is adjusted for a smaller pitch diameter than standard (or larger, for that matter) the die will cut a pitch that is slightly shorter or longer than if set to precise pitch diameter, even then long screws cannot be counted on to be an accurate pitch in their full length, this is why long screws are single point threaded in the lathe or thread milled, or finish ground.


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## riversidedan (May 13, 2021)

AARON W ............you hit the nail on the head!


Personally I find using a tap or die easier than single point, but that is because to single point I usually have to use change gears or have to set up a threading accessory


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## benmychree (May 13, 2021)

A tap will nearly always cut a good thread to size, you cannot say that for cheap button dies, bad finishes and drunken threads are all too common.
  I have never had to thread on a non QC lathe, but I can sympathize on having to swap nasty dirty change gears.  When I have to thread special pitches on my lathe, I have to go through the same mess, even though I do not lube them with anything but oil.


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## Ultradog MN (May 14, 2021)

If you are doing production work where time is a big factor then using a die is probably the way to go. But imo, few turning jobs are as satisfying as single pointing a set of threads. 
I cut quite a few threads while I was in the Navy 45 years ago. Didn't run a lathe but a few times since then. About 6 years ago a friend needed to make a new mandrel for a buzz saw for his tractor. 1 1/4x7 threads iirc. He had a new Grizzly 12x30? but didn't know anything about machining  so he asked if I could still cut a set of threads. I said I think so and showed him how.  It all came back to me as I went. I ground the tool, figured the depth to cut (.750/N) and cut them to fit a new nut he had. It took us half a Saturday to do it but time was not an issue.
They came out perfect and he was both pleased and amazed to watch it all happen.
I'm just getting back in to a bit of machining after a looong hiatus. Bought a lathe a couple of months ago and am looking forward to cutting some threads. So I say give it a try on some scrap. It is simple, enjoyable and satisfying to do.


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