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Hex die holder for lathe

robbor

Aluminum
Joined
Feb 18, 2008
Location
Los Angeles Ca
Im in need of some sort of holder for the tailstock of a lathe 3mt to hold hex dies for threading. So far all ive seen is round holder that go in a drill chuck from the looks, pretty unimpressive.
 
Hex dies are used to repair existing threads. They're meant to be turned with a wrench.

Threading dies are usually round with a depression for a retaining setscrew, designed to be used in a die handle. These are used to cut new threads.

- Leigh
 
Hex dies are used to repair existing threads. They're meant to be turned with a wrench.

Threading dies are usually round with a depression for a retaining setscrew, designed to be used in a die handle. These are used to cut new threads.

- Leigh

But you can also buy carbon steel threadcutting hex dies. Snap-on, Sears, Mac, Hansen and others sell them, often in big sets with matching taps, die stocks and tap wrenches. Such sets have been sold for decades and are common.

For lathe work, I only use round dies or Geometric die heads. I have a collection of very high quality tailstock round die holders in various sizes.

Larry
 
My neighbor just made such a holder. He made it in the traditional fashion, taper mounted and sliding. For the holder he used a suitable 6-point socket with grub screws tapped in it to hold the die. Easy and cheap. biggrin Greyson
 
But you can also buy carbon steel threadcutting hex dies. Snap-on, Sears, Mac, Hansen and others sell them, often in big sets with matching taps, die stocks and tap wrenches. Such sets have been sold for decades and are common.
Very true.

They're designed for hand use, not machine use.

- Leigh
 
Yes but they are for thread repairs, not cutting new threads...

Commonly called die nuts here...

My point is that there are two completely different kinds of hex dies.

There are rethreading tools for renewing damaged threads. Those dies have the same hex size as a standard nut of the thread they fit. They are turned with a mechanic's wrench of the appropriate size, not a die stock. For instance, a 3/8-16 rethreading hex die has a 9/16" hex, a 1/2-13 die has a 3/4 hex, etc. Such tools are often sold in a wooden case with a pair of thread files.
Examples: http://www.irwin.com/irwin/consumer/jhtml/browse.jhtml?catId=IrwinCat100492

But there are also sets of taps and dies designed for cutting new threads as well as rethreading. Such sets are available with either round or hex dies. The hex sizes correspond to the diameters of the same thread size round dies, 5/8", 1", 1 7/16", etc. These sets are sold in hardware stores, mechanics tool trucks (Snap-on) and department stores like Sears. In other words, they are meant for hand use by DIY and mechanic type users, not by machinists. They are usually carbon steel and of rather cheap construction, as the buyers expect for the price paid. The die stocks are designed to hold either hex or round dies.
Examples: http://www.irwin.com/irwin/consumer/jhtml/browse.jhtml?catId=IrwinCat100477
http://www.irwin.com/irwin/consumer/jhtml/detail.jhtml?prodId=IrwinProd100472

Larry
 
These sets are sold in hardware stores, mechanics tool trucks (Snap-on) and department stores like Sears. In other words, they are meant for hand use by DIY and mechanic type users, not by machinists.
This board is for machinists.

Why would you discuss tools which are not designed for such use? :confused:

- Leigh
 
because robbor, the OP, asked about "... some sort of holder for the tailstock of a lathe 3mt to hold hex dies for threading...."

so the different types of HEX dies were discussed. including some not meant for machinists.

since you were asking....
 
Most hex dies are carbon steel and will not hold up to threading but will clean up bad threads ok most the time. I have a set of hex dies that are HSS and I have used them to cut new threads and I can tell you they don't work as well as a round threading die. I don't know why that is but it is.

I don't cut new threads with the hex dies and I suggest to you it's not worth trying. As to the hex dies not being for machinists, that is hogwash. Many machinists use them when repairing machinery, etc.

As to carbon dies of any kind, your wasting your money if you buy carbon.

Now, using a round or hex die in the tailstock is problamatic. There is an alignment problem in that the die has to be perfectly centered if the holder is of the solid type. If it's the floating type you have a better chance to get a good thread.

Single pointing the thread or using a geo diehead is the best way to go.
 
I have two sets of Kromedge dies by Craftsman. One is hex, the other is round. I prefer the round because they are split and can be adjusted slightly. They also fit the tailstock mounted die holder I made for the lathe. The die holder has some float to aid in alignment. I usually prefer to single point but if the work is long and thin I will single point for a few passes then switch to the die holder.

I also have a set of thread chasers from Mac tools. It looks to be carbon steel. I rarely use them. When I do, it is to clean up threads on studs when doing repair work. I run them up and down the studs with some cutting oil and an air ratchet.

I have plenty of good round dies so I have no need or plans to make a die holder or adapter for using them on the tailstock mounted holder.

McMaster-Carr has hex adapter for round dies so one can use a wrench or socket.

-DU-
 
Im in need of some sort of holder for the tailstock of a lathe 3mt to hold hex dies for threading. So far all ive seen is round holder that go in a drill chuck from the looks, pretty unimpressive.

Hex dies are little more than useless. They are for the most part carbon as has been stated. There are tail stock round die holders you can buy.

http://www.mcmaster.com/#threading-die-holders/=21ueto

Or you can make one like this.

Tom
 

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As to carbon dies of any kind, your wasting your money if you buy carbon.
...snip....

I have one of those Snap On carbon steel tap and die sets, and I don't thing it was a waste - I knew it's history (only the 1/4-20 die had been used out of the like 70 oiece inch metric set) - guy had gone bankrupt, needed the cash, was asking $20 - for that price, to get the sizes I've used oh, 1x/2x in the last 10 years, worth the cash. :D

Buy them at "new price", yeah, you're right
 
Hex dies are little more than useless.

I would be having NO idea how the outside shape of a die would affect its thread form or how that outside shape would make it "useless" for cutting a thread.

And, carbon steel is perfectly capable of cutting metal. Your grandfather (great-grandfather for the whippersnappers) probably used it exclusively for cutters, dies and taps. Threading is slow and not likely to overheat anything. Carbon steel can be made harder than many HSS types. But it probably will wear faster.

That said, I consider ANY non-adjustable die to be pretty low on the scale of what I want to use.

It's enough trouble to make a holder for hex dies, that you kinda need to want to badly. And when you are done, you have a specialty tool for holding non-adjustable dies......

hex and round dies for cutting and repairing threads, both.... for the die-hard skeptics. Re-threading dies are hex so a mechanic can use them with a wrench. Hex thread cutting dies are hex so you have to buy the holder from the supplier also.

dies.jpg
 
JST, I don't think the hex has anything to do with why they don't cut new threads well. It's been my experience that the hex dies don't do as good a job cutting new threads and I have tried them many times using the HSS type. I can only guess that it has to do with the shape of the cutters but they seem to tear metal more than the standard threading dies. Even the round threading dies can and do tear the metal if not carefull lined up straight on the shaft and carefully advanced on the work.
 
JST, I don't think the hex has anything to do with why they don't cut new threads well. It's been my experience that the hex dies don't do as good a job cutting new threads and I have tried them many times using the HSS type. I can only guess that it has to do with the shape of the cutters but they seem to tear metal more than the standard threading dies. Even the round threading dies can and do tear the metal if not carefull lined up straight on the shaft and carefully advanced on the work.

It's probably because they are made for use by folks that don't do machine work...... And hardly ever thread a rod or whatever. So they are often made cheaply, because they are regarded as almost "filler" material..

I was given a big set of Sears hex dies and taps many years ago (OK, maybe 10 years ago). I found the taps were fine, but the dies wouldn't start well, wouldn't cut well, and weren't even centered in the hex. I returned the set.

Now, I have a set of OLD hex Sears dies, probably 40 years old now, and those are fine. Centered well, good lead-in, their only problem is they are not adjustable. That's one of them in the picture.
 
Hex dies

Well right now thats all i have. My dies are the small hex like in JST's picture, the crapsman ones, 2 big sets. Im about to buy some spiral point taps because hand taps suck so bad but i dont use dies much at all, all my work is one off personal jobs. Now answer me this if hex dies are not for making threads then why is one side heavily beveled like the end of a tap? I cant say they impress me with their finish but they get the job done. Id prefer to have the round adjustable dies as i know they cut better but not unless i can get them dirt cheap. If you have a set around you dont want feel free to send them to me:D. I was given a broken lathe, and also have a really old atlas, when i fix the new one i could always single point cut threads.
 
If you want get qualitt

Well, the saying "you get what you pay for" applies to many things. Anything having to do with machining is one of them.

Tom


This is very true!!! If you want great quality I wouldn't buy your piece off the shelf. Visit a well established manufacturer. Visit Taylor Tool they have a huge stock and do specialty requests as well.

If you are not satisfied with the tool you can always return it for a refund!
 








 
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