View Full Version : Threadex Floating Die System

04-26-2010, 05:56 PM
I won a pair of new 1" Threadex Floating Die Heads (http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=370&PARTPG=N2DRVSH&PMT4NO=0&PMITEM=00475228&PMCTLG=00&PMT4TP=*LTIP).

The heads came without the necessary shank, so I am not able to
try them yet, but I am curious to hear from anyone familiar with
their operation.

As near as I can tell, the shank has a slot that a pin in the head
engages to prevent the head from rotating. The head is then
free to slide fore/aft along the length of the shank, travelling
as its die threads a blank mounted in a chuck.


Michael Moore
04-26-2010, 10:41 PM
That's the way mine works though if you zoom in on the catalog photo you can see the shank has splines. I've only used it once or twice so far but it seems to work pretty slick. Definitely easier than trying to get the die started and then threading it on by hand.


04-27-2010, 12:34 AM
Thank you.

There is no mention of workpiece preparation in the instructions. Do
you chamfer the end of the material or proceed with an as-cut face?
Can the head be pressed up to the face at threading speed to initiate
the operation, or does one need to start the die by hand, then proceed
under power?

These Die heads are rated for a Max Thread Length of 3". Does the
die head travel along the shank (pulled by the threading action)?

In the event that one miscalculates and does not stop the operation
in time, is the head merely pulled out beyond the reach of the splines
on the shank and begin to turn harmlessly with the workpiece?


04-27-2010, 01:04 AM
I have that exact setup, with a two or three different size die holders. The way I use it is to push the die up against the stock to be threaded firmly. Then, while keeping pressure on the tailstock screw, I start the lathe up. The die starts readily and pulls towards the headstock, then I hit the reverse and let it feed off. It does a good job, but doesn't work that well on 304 in smaller sizes at least. Just rips or twists the material. On brass its fantastic and if you bump your speed a bit the surface finish is mirror like.

04-27-2010, 01:11 AM
Very helpful to know.

Did you purchase your Threadex parts on-line, if so, from which vendor?

I was a little surprised to see how much MSC lists the shanks/arbors
for. Reading above that they are splined instead of just having a single
groove went some distance towards explaining the price.


04-27-2010, 07:02 AM
The Threadex appears to be about as good as you can get using those type threading dies.

The big problem is the thin dies. These dies rely on the few threads behind the cutting edges to maintain correct thread pitch. It's a battle between the cutting edge and the remaining non-cutting threads to maintain pitch.

With only a few non cutting threads it's difficult to get accurate pitch threads like is possible with production die heads with much longer sections of non cutting, guide threads.

Be sure to get good quality high speed steel die$. The cheapo hardware store carbon steel dies are no good for anything but restoring damaged threads. Use plenty of heavy cutting oil.

Also, in use, be sure to not let the shavings build up in die.