# Die Head and chasers



## workinforwood (Oct 21, 2009)

I was checking out this guy was selling tons of different sizes of die chasers.  I asked what would they be for and he shows me a pic of a die head.  So that's one spiffy looking tool that they say "is the best way to thread".  Maybe it is or not..whatever.  I'm having a hard time finding much info online about the actual device and not that many manufacturers are out there, but the prices are not bad at all, at least not compared to what the triple lead tap/die sets were sold for here. What's the question?...got lots!

It appears to have 4 chasers.  So does it only cut 4 start threads, or can it cut anything from single start to 4 start depending on what you want?

Obviously you need different pitch/depth/tpi chasers unless you only just want to cut one type of thread, but what about diameter of threads?  If I am threading a 3/8 rod and next time I want to thread a 1/2" rod, do I need a different die head because of the diameter, or will the original die head handle an assortment of outer diameters?

What about inside threads?  If the die head cut a triple or quadruple  start thread on the outside, how the heck am I going to match that on the inside?  A male thread is useless without a female mate.  Is there a die head tap that is the opposite of the die head die  <pardon my terms hehe> If there is a special multipurpose type tap that teams up the the die assembly, how could it fit in such a small place like a pen that might only be 7mm ID ?

How does one attach a die head on a lathe?  It seems like the one's I saw attach to the drive spindle.  I'm guessing you actually turn on the lathe, the head spins and drives in to the part until it bottoms out which causes the head to open up like jaws, so the chasers are not cutting anymore which would damage the threads you just made.  And then you have to come up with some way to hold the part being threaded in the tailstock?  :hypnotized:  

It's not like I have to know all this stuff, but I do at the same time.  I'm quite curious about it, the technology, application and hey..maybe this is something I need to consider for personal use.


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## skiprat (Oct 21, 2009)

Jeff, my humble suggestion would be to forget you even heard about them unless you are thinking of getting a CNC lathe:wink:


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## JeffinWIS (Oct 21, 2009)

Jeff, search "geometric die head".   The four chasers cut a single lead thread.  Someone MIGHT make you a set of multi start chasers...$$$$$$, but I have never seen that.  The die heads are made with different style shanks to fit a tailstock quill, turret lathe, or QC toolpost.  I'm fairly certain a geometric die head would not work on "plastic" the size of a pen...the pressure required to release the chasers would likely just tear the threads off the blank.  And you would still need a tap to make the matching female thread.  If you get a CNC lathe, no geometric die head needed...you can "single point" any thread in a minute or two with minimal tooling required.


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## KenV (Oct 22, 2009)

Yup Jeff -- always more tools to buy and learn to use.....   CNC combines several bad habits and moving parts to do some serious magic!!!


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