# Problems Adding External Threading Using a Die



## jacobbaldwin (Aug 24, 2020)

Hello, everyone!

I'm running into some issues when attempting to add some external threading to components for a fountain pen I'm making. I've tested with various materials, and I'm just not getting the results I need.

I'm turning down the particular pieces to 10mm diameter, and then am using an M10 x 1.5 die to add threading. However, every time I attempt to add threading, it chews the part up and doesn't leave the threading behind, which gives me nothing more than a 8.7mm diameter (and worthless) piece. The picture below is an example I just did using hardwood, but I've also tried with an acrylic, and I'm getting the same thing. As a side note, when using a tap I'm not having any issues adding thread to the inside of the pen's barrel. This just confuses me further...

Does anyone have advice on how to add threading properly to the exterior of whatever materials you are using to make fountain pens?

Thanks,

Jacob Baldwin


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## monophoto (Aug 24, 2020)

What kind of material are you using?  It looks like wood - my experience is that attempting to do a male thread in wood using a die is an exercise in frustration.

Cutting a female thread in face-grain wood using a tap is usually possible, and I've had some success using a tap to cut female threads in some end-grain wood, but that's really timber-specific.

My sense is that most bespoke pen makers use plastic or ebonite.  Where the intention is for the pen body to be wood, the usual approach is to embed threaded plastic inserts in the wood that are hidden when the pen is capped.


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## Mr Vic (Aug 24, 2020)

Jacob if you are tapping by hand in the vice the I would say you're getting wobble on the die and eating the threads as fast as you create them. Also look at your die. Some have a slight taper to the hole. That's the side you want to tap into. Do you have a die holder for your tail stock? If not, leave the piece chucked up anyway, center the die and apply pressure with the tail stock while turning the piece with the head stock.

Trya search on tap and die. or threading. A bunch of threads on the subject


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## duncsuss (Aug 24, 2020)

Jacob - I can think of so many possible reasons to explain the difficulties you're facing, and they might all be wrong but here goes:

1. Wood - I can't do it either, and I don't know anyone who has success using a die to cut threads in wood.

That said, if you are also having problems with man-made materials: avoid polyester resin, avoid inlace acrylester. Acrylic acetate is good, alumilite is good, ebonite (hard rubber) is good - meaning "takes threads without fighting every last inch of the way".

2. The die you have: what shape is it - hexagonal or circular? Because Hexagonal dies are not for cutting new threads, they are for "chasing" (cleaning out) existing threads. You will need round dies to cut new threads.

3. If you have a round die, then try making the tenon a little smaller than major diameter of the thread you are about to cut. With M10 x 1.5, I would probably turn the tenon down to 9.8mm diameter - that's only 100x(0.2/1.5) percent of the full thread, 13%, which leaves a full 87% of the thread to hold. That's plenty.

4. Chamfer the end of the tenon so that the die doesn' have to fight to get started. With M10 x 1.5, I would chamfer at least 2mm at the end of the tenon, at 45 degrees. I want the first cutting thread of the die to slip onto the end of the tenon.

5. Holding the workpiece and the tool: looks like you have the workpiece held in a vice which suggests you are hand-holding the die in a die wrench (or whatever the name for them is). I'd look for something that helps you keep the die from twisting out of alignment: many people have a die holder that fits into the lathe tailstock or slides on a rod held in a tailstock-mounted drill bit chuck. They are a great investment - hold the pen barrel in a collet chuck in the headstock, lock the spindle, and gently screw the die onto the tenon. Everything held in alignment, works nicely.

Hope this helps you get started -

Duncan


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## howsitwork (Aug 25, 2020)

Duncan has summarised the answers to you issue . I would add that few woods are “easy” to thread and without a tail stock die holder and adjustable dies ( circular ones with a slit are adjustable) you are making your life much more difficult. Applying wax to lubricate the wood to be threaded makes it a bit easier and keep applying it, I use paste wax when hand thread chasing but I don’t normally use dies. 

Hard wood containing natural oils such as Lignum vitae apparently work well ( not tried personally ) but boxwood , holly  and beech all take good threads in my ( limited )experience.  Lots of past wax definately helps when hand thread chasing as does a perfectly polished tool rest and hand rest .

Have a look at 



 where a true master of hand thread chasing shows you how . It’s not easy but very satisfying ( when it works ) .


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