Thread size for Parker pencil mechanism?

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duncsuss

duncsuss

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Cwalker935 said:
I am trying to figure the right tap for the Parker Style Pencil Mechanism - 0.5mm:

https://www.beartoothwoods.com/catalog/product_info.php?products_id=4996

It's very close to 7/32 - 32 but not quite it. I am not versed in tap and die sizing and need some help. I am thinking an m5.5 or m6 x .5 tap might be the proper tap. Any help would be greatly appreciated.
Click to expand...

I haven't tried making any of these, so I can't offer an answer -- but have you asked Bear Tooth Woods?
 
Cwalker935

Cwalker935

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duncsuss said:
Cwalker935 said:
I am trying to figure the right tap for the Parker Style Pencil Mechanism - 0.5mm:

https://www.beartoothwoods.com/catalog/product_info.php?products_id=4996

It's very close to 7/32 - 32 but not quite it. I am not versed in tap and die sizing and need some help. I am thinking an m5.5 or m6 x .5 tap might be the proper tap. Any help would be greatly appreciated.
Click to expand...

I haven't tried making any of these, so I can't offer an answer -- but have you asked Bear Tooth Woods?
Click to expand...

They did not know.
 
B

bmachin

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32 tpi is not close to .5mm. It is much closer to .8mm. (1/32"=.793mm). (.5mm=.020"). (.75mm=.030")

Sorry, but it's the only help that I can offer. You might take these numbers to victornet.com and check their taps to see if they have any metreic taps that appear close.

Bill
 
magpens

magpens

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I trust your word, Cody, but reading your reference to 7-32 caused me some surprise. I looked up the clearance hole size for that and find it to be something like 0.16", if I am interpolating the reference table correctly. That is quite a bit smaller than the 5.75mm (0.226") size of the thread stated by Milan.

Even a 7-32 tap is "non-standard". But Victornet does have them and I bought a couple for a special purpose I have related to using the click mechanism out of a Slimline Pro to make a so-called "kitless" pen. Turns out that the "stub" of that click mechanism is threaded 7-32 for screwing on a pushbutton.
 
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BRobbins629

BRobbins629

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Haven't measured that one, but attached is a concept I have used many times. Measure the OD over the threads and size the tap just a little larger. Take a picture of the threads next to a steel rule, blow up the picture and count a number of threads that comes close to lines on the rule. Do some calculations, and it should work. The attached was from a Pentel Pencil nib and bought the taps on EBay.
 

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Cwalker935

Cwalker935

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The OD of the threads is exactly 7/32 or around 5.6 mm, using Bruces's thread counting method I get .75 mm or 34 tpi. Given that the Milan's pens info seems to be right. That solves one problem but raises another- where to find a m5.75 x .75 tap. I am not having any luck finding one and wonder if a m6 x .75 would work. Any thoughts?

Thanks for all the help.
 
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