# What thread size?



## Omnimill (Jun 20, 2011)

I've got a Lansky Knife Sharpener which I'd like to modify but I'll need to buy a new die to thread some rod - but what size die?!
The thumb screw (which holds the guide rod) is 3/16 diameter and has 24 threads to the inch. So is it 3/16" UNC or 10-24 (whatever that means!)

Here's the thumb screw on the end of the stone:

http://www.protoolreviews.com/revie...rd-deluxe-knife-sharpening-system/lansky4.jpg

Thanks in advance.

Vic.


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## mklotz (Jun 20, 2011)

10*0.013 + 0.060 = 0.190 (very close to 3/16")

It's almost certainly a common 10-24


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## mike4517 (Jun 20, 2011)

Hi Vic
Does this help


http://www.zytrax.com/tech/mech/threads.htm
Mike


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## Omnimill (Jun 20, 2011)

Thanks guys, so is 10-24 and 3/16 UNC the same thing?

Would you believe it's just as cheap to buy a HSS die on eBay and get it shipped from the USA as it is to get a CS one over here!

Vic.


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## mklotz (Jun 20, 2011)

Omnimill  said:
			
		

> Thanks guys, so is 10-24 and 3/16 UNC the same thing?



Below 1/4", the UNC standards *are* the numbered series*...

http://www.efunda.com/designstandards/screws/screwunc.cfm

so, no, 10-24 and 3/16-24 aren't the same thing, though very close. I won't say categorically that 3/16-24 doesn't exist - there's always some jerk making proprietary threads - but in seventy years of fiddling about I've never encountered it.

---
* As if the idiot Imperial fractions weren't bad enough, they had to muck things up with numbered threads using a system that directly conveys no dimensional information whatsoever. (Don't ask me what I *really* think of America's treasured collection of stupid measures.)


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## steamer (Jun 20, 2011)

Your right Marv....

How about #28-16 NS  obsolete as of 1950.....which is parked right in between 3/8 and 7/16 in size. :

there's hundreds of them!

Dave


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## Omnimill (Jun 21, 2011)

This should do it then:

http://cgi.ebay.co.uk/10-24-X-13-16...Work_Holding&hash=item45f0df29b1#ht_500wt_922

Thanks again!

Vic.


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## tel (Jun 21, 2011)

Or is it a common ol' 3/16 Whit?


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## Omnimill (Jun 21, 2011)

It was a thought Tel, but the Lansky Sharpener is made in USA so I expect not?!

https://lansky.com/

Vic.


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## tel (Jun 21, 2011)

might be worth trying one tho'


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## Omnimill (Jun 21, 2011)

I looked for a 3/16 Whitworth bolt last night and couldn't find one 

Vic.


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## MachineTom (Jun 21, 2011)

There has been a 3/16-24 tap moving around my tool box for decades unused. So I just went to where it should be and of course could not find it. Opened up my 1952 MHB and the only 3/16 listed was Whitworth, also fine thread of 3/16-32 along with the somewhat less common 7/32-28.


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## around (Jun 22, 2011)

Measured my Lansky Thumb screws and checked them with a die. It is 10-24 NC

Cheers,

Adrian


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## Omnimill (Jun 23, 2011)

Thats lucky, thats what I've just ordered! 

Vic.


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## tel (Jun 23, 2011)

I'd still like to see you try a 3/16W - just as a matter of interest.


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