How to know what size tap to use for a threaded component?

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spindlecraft

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Apr 6, 2014
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Philipsburg, PA
As I am just getting started with kitless pens, I decided to "ease in" to it a bit. I recently purchased a couple of these:

https://www.woodturningz.com/Fountain_Pen_Conv_Kit_-_Black_Chrome

to at least get me started. But - I need to know what size tap to get, to drill the inner threads of the pen body. Does anybody know either a.) What size thread this product has, or b.) how to figure out what size tap I would use to accommodate this product?

Any information would be greatly appreciated.

Thanks!
 
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monophoto

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As I am just getting started with kitless pens, I decided to "ease in" to it a bit. I recently purchased a couple of these:

https://www.woodturningz.com/Fountain_Pen_Conv_Kit_-_Black_Chrome

to at least get me started. But - I need to know what size tap to get, to drill the inner threads of the pen body. Does anybody know either a.) What size thread this product has, or b.) how to figure out what size tap I would use to accommodate this product?

First, the components you have purchased are intended to convert a kit rollerball from a specific manufacturer into a fountain pen. Unfortunately, there is no guarantee that the threading used by the manufacturer of this line of kits is the same as that used by other kit manufacturers. Or even that this manufacturer will continue to use the same threading in the future. So what that means is that while you can set yourself up with the tooling required to use these components in kitless pens, you may have to switch to something else in the future if you buy components from some other manufacturer or it the manufacturer changes his design. That's not a showstopper - just something to be aware of.

The other issue is that some kit manufacturers are 'vertically integrated' meaning that they make all of the components that go into their kits. In that situation, you basically have to either get the thread specification from the manufacturer, or you have to measure it yourself. And this is the situation where the threading might change on components that you buy in the future. On the other hand, some kit manufacturers opt to purchase components (and especially fountain pen components) from one of the major suppliers (notably Bock or Jowo), and in that case, the threading is well known. Also, if the kit manufacturer is sourcing sections from a speciality supplier, it is less likely that the threading would change in the future - and that also means that there are many other places where you can purchase those components.

Because most pen kits are made in Asia, its a good bet that the threading on the section is metric, and in metric shorthand,, would be specified as MX-Y. To determine the tap required to make a pen body for this section you need to determine two measurements. X is the diameter of the cylinder over the peaks of the threads - that's easily measured with a caliper, preferably one with a digital readout. I think that in most cases, X will be an integral number, eg 8mm, 9mm, etc.

Y is the pitch in threads per mm. You can purchase thread gauges to measure thread pitch, but the problem is that most gauges are designed to work with standard metric screw/bolt threading. Unfortunately, the threading used on pen components does not have to confirm to standard nut/bolt threading, and may be an 'odd' number. That's where things get tricky. One option is to measure the pitch by counting the number of threads over the length of the threaded portion of the section, and then divide by the measured length (in mm) of the threaded portion. Do that several times and average the results.

But the bottom line here is that it is likely that the tap you will need is not a standard metric tap that you can find at the hardware store or in a tap and die kit from one of the tooling supply houses, and in particular, the non-standard aspect will the the pitch, Y. Periodically, someone organizes a group buy on this site to obtain specialty taps and dies for kitless penmakers and that includes the more common threadings used for pens. That might be your best bet for sourcing the tap you need. But because its special, it will be more spendy that a tap from the hardware store.
 

magpens

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Coquitlam, BC, Canada
Louie has said it well.

I have not found one source of info that covers all nib thread possibilities.

A reliable source of info for one common Bock nib is BeaufortInk.co.uk ....



And here is some info for one Jowo nib ....

 

mredburn

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DIgital calipers measure the outside diameter of the threads. Metric thread gage to measure the pitch. If your going to go kitless both will be needed. Hopefully someone has a unit that they can measure and let us know. If you go truly kitless you can just design the threads size and pitch to suit you, and make the parts as you want.
 

Penchant 4

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Great Lakes Area
Possible sources for some of the 'more common' kitless taps and dies/specialty tools/parts are: Jim Hinze; Turners Warehouse; Beaufort Ink (UK). This is by no means an exhaustive list, simply the first that come to mind.

Some of the kitless tap/die sets are multiple start, too. That is to say that rather than there being one continuous line of thread from start to finish, that the tap/die cut two or three (or perhaps more) threads. This is something to watch out for and will raise the price of the tool.

In addition to the taps/dies, you will need the specified size drill bit for each tap. There are tables of this information available on the internet.

Good luck!
 

bmachin

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Jul 28, 2013
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Owensboro, KY
I think that your best bet is to save yourself some headaches that you don't need and scrap or return what you've got. Then buy the El Grande nib from Berea Hardwoods.


Get the readily available and inexpensive metric 10x1 tap and you're ready to go.

This book is well worth the price of admission with materials and tool lists and step-by-step instructions. Has plans for a pen based one the El Grande/Churchill section:


Buy It!!

Bill
 
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