At a recent garage sale I picked up a item that would hold a die
and then be the chucked in a tailstock. It was meant to hold
a round die. On the way home I realized the my dies are hex
shaped. I can remove the inner piece that the die sits in and
replace it with one that can hold my dies.
So basically I need to have an OD that is round and an ID
that is hex shaped. Doing the OD on a lathe should be easy.
Problem is, how do you make a hex ID? I don't have anything
that I can use for a punch.
I made such a beast using the business end of an appropriately sized 6 point
socket. I machined a pocket in the holder and cut the end off the socket,
faced it square and TIGed it in place. Looks like it was made from the
Hex-shaped dies are normally rethreading dies, Wayne. You might want to
look into buying a set of threading dies, I think they might work a lot
better for you.
Further, in my set of rethreading dies (hex outside) the outside hex
dimensions aren't constant across the whole set. So one hex insert
wouldn't do ya.
Probably the easiest way to make this would be to make it in 2 parts
and then weld it together. Carefully. You can stroke it using a shaper,
or you can stroke an internal shape using a lathe or mill if you know
how. You can cut a rough hole using a plasma cutter and then file to
shape. You can chain drill and file. You can drill it and break a bandsaw
blade and pass it through and reweld it and carefully saw the inside. You
can drill it and pass through a saw blade you can use with your die filer
if your die filer has the saw attachment. You can drill little holes in
the corners and then bigger ones in the middle and then broach out the
remainder using a hardened and ground hex wrench of the correct size. It
all depends on how much work you want to do.
It would have been a lot easier to just leave the tailstock die holder
back at the garage sale! :-)
Hex dies are normally a fixed size.
Circular dies are split so that the size can be altered slightly. That's
what the 3 screws on the die holder are for. The central one screws into the
split to push it apart and increase the size, the outer two squeeze the die
together to close the split and make the size smaller. Many close tolerance
applications require the thread to comply to certain limits and fits. A
better finish can be achieved on some steels by cutting the thread in two
The hex type are particularly useful for repairing a damaged thread,
especially where it cannot be removed. Hence the term rethreading or thread
There are a number of fixed size dies becoming available. Generally these
are cheaper and their quality can be suspect. I have only had one set in UK.
Couldn't tap butter with it. That set is some years old and quality may have
improved but you cannot beat a real die from a well known maker, US or
||Hex-shaped dies are normally rethreading dies, Wayne. You might want to
||look into buying a set of threading dies, I think they might work a lot
||better for you.
What is the difference in the way they cut?
Texas Parts Guy
Hex rethreading dies are normally the same size as the nut used for that
size thread. Thus they come in many sizes.
There are also fairly common hex dies intended for home-workshop uses,
and sold at home centers and hardware stores. These are all the same
sized hex, something like 1" across the flats. It is most likely these
that you have. They are probably not the best quality, but adequate for
Yup, and they work like crap for threading new stuff. Sears used to
have decent split round button dies, I've got a bunch, carefully
hoarded. These days, about all you can get is Hansen from the
hardware store, if you can find a hardware store, and they're hex
dies. Those also work like crap for originating threads. One local
hardware store carries Varmint American dies, those are round, but not
split, marginally better than the hex ones but not much. MSC, et al,
seem to be the only places you can buy decently working split
threading dies these days. The hex dies don't seem to have much of an
edge, they just kind of roll the threads instead of cutting them.
There's also no adjustment possible with them. They leave very ragged
new threads, where they leave threads at all. I had one chunk of
aluminum just turn into a passible imitation of a fir tree twig after
I ran one of those hex dies over it, even with cutting compound. A
round split button die left polished threads on the same chunk. The
stuff was some of that nasty, extruded, home improvement-joint rod
stock which machines like bubble gum, but it does show what's possible
with the right tooling.
Hex dies are good for debuggering studs and bolt ends in places where
you can't swing a regular die stock, you can just hunt up the
appropriate socket or wrench and use that. IMO, they just aren't
designed for originating new threads and would probably work very
badly, if at all, in a tailstock holder.
I didn't know of the difference when I bought mine. I got the HSS set from
from Sears several years ago in a catalog sale. I did thread a 1/2 steel
rod yesterday as a test. It was very slow going, but looked ok. With
the adjustables would you start with it larger, then go over it again
at the proper size? Would it thread faster that way?
I threw in a 1/2 alum rod in the lathe yesterday as my 1st attempt
to thread on it. I was thinking you can cut aluminum faster so I didn't
set it on a slow speed (Braing cramp). The carriage hit the microstop and
pushed it into the headstock. Then the shear pin broke. (It took a while to
figure out why the leadscrew wasn't working after that.) Now I know
what the pin was in the toolbox was, a spare shear pin. After that I got
a thread made. Not perfect, but not bad for my 1st try.
I did see Enco has a cheapy HSS set with adjustable dies.
Anyway I might need to make some english/metric adapter studs for
my younger brother. It seems like threading on the lathe will be
faster than doing it by hand with a die.
You are probably right, but it looked so cool!