Subject: Anyone know about these threads?

From: [email-masked] (Clive Washington)
Date: Mon, 28 Mar 1994 07:54:09 +0000

I've just found some taps and dies that I'm not familiar with,
nor can I find them in my thread tables or data books.  They are
labelled with markings like "0-80 UNC" and "2-56 UNF".  They don't
seem to form part of the UNC and UNF series I know about (which are
in the 1/4 "  and up scale).  These threads are in the 0.5-2mm size
range, and initially I thought thay were small BA series.

I've never seen any nuts or bolts with these specifications either.
I can buy these taps and dies surplus, cheap, all HSS, GT, but
there seems th be no point if I can never match them up with
anything. (OK, I admit it, I bought a few anyway, and am wondering
if it's worth going back to clear them out!)

If anyone can tell me anything about them, I'd be grateful.  Perhaps
they are known more widely in the US. 

Incidentally, I got a similar bargain last week. I saw a set of
12 BA taps, Left Hand! for £3, so I snapped them up.  List price was
over £80.  God knows what I'll use them for.  Anyone out there got
a LH 12BA die they don't want?

Clive W.

-- 
!!!According to my contract, this place owns my opinions!!!

---

From: [email-masked] (Kevin P. Martin)
Date: Tue, 29 Mar 1994 16:43:11 GMT

>they are known more widely in the US. 
If the 0.5-2 mm is the tap diameter, I would guess that these are really
small sizes of the "numbered" screw sizes. A more popular size you might
encounter is 8-32 (which is very close to 1/8"-32, to the point where
a bolt of one size fits the nut of the other, but not vice versa).

I have a tap which is (I believe) 5-40; it is about 5/64" diameter.

Pretty well any machine screw under 1/8" has a numbered size here.
Number 10 screws (>1/8") are fairly common, and I've run into
number 12 and number 14 occasionally.
I don't know how much these are seen outside North America.
   -Kevin Martin, Thinkage Ltd., Kitchener, Ontario, Canada

---

From: [email-masked] (Gordon W J Sorensen)
Date: Tue, 29 Mar 1994 21:09:47 GMT

Clive Washington ([email-masked]) wrote:
: I've just found some taps and dies that I'm not familiar with,
: nor can I find them in my thread tables or data books.  They are
: labelled with markings like "0-80 UNC" and "2-56 UNF".  They don't
: seem to form part of the UNC and UNF series I know about (which are
: in the 1/4 "  and up scale).  These threads are in the 0.5-2mm size
: range, and initially I thought thay were small BA series.

: I've never seen any nuts or bolts with these specifications either.
: I can buy these taps and dies surplus, cheap, all HSS, GT, but
: there seems th be no point if I can never match them up with
: anything. (OK, I admit it, I bought a few anyway, and am wondering
: if it's worth going back to clear them out!)

Here in North America those types of designations are quite common for screw
sizes under 1/4 inch. A 6-32 refers to a number 6 sized screw with 32 threads
per inch. A 10-32 is a number 10 screw with 32 threads per inch, its 
companion for coarse threads is a 10-24. I am not sure how they determined
what the 10 or the 6 relates to, but a number 10 is about 3/16 inch in diameter.
Maybe the number 10 referred to the number of royal finger nail thicknesses 
of some early monarch, much like the basis for the inch, foot, and yard. Ah
some day maybe we will get around to using the metric system.

0-80 is pretty small. I use them and 1-72 and the 2-56 in making model steam
engines. The hobby shops around here have brass screws and nuts with hex heads
on them which make for realistic looking bolts for models.

Gun smiths have all sorts of odd ball sizes especially in the threads per inch.
If you were in the states, I would say you found a good bargain.

gordon s.

: If anyone can tell me anything about them, I'd be grateful.  Perhaps
: they are known more widely in the US. 

: Incidentally, I got a similar bargain last week. I saw a set of
: 12 BA taps, Left Hand! for £3, so I snapped them up.  List price was
: over £80.  God knows what I'll use them for.  Anyone out there got
: a LH 12BA die they don't want?

: Clive W.

: -- 
: !!!According to my contract, this place owns my opinions!!!

---

From: [email-masked] (Nathan Mead)
Date: 29 Mar 94 12:52:31 MST

In article <[email-masked]>, [email-masked] (Clive Washington) writes:
|> I've just found some taps and dies that I'm not familiar with,
|> nor can I find them in my thread tables or data books.  They are
|> labelled with markings like "0-80 UNC" and "2-56 UNF".  They don't
|> seem to form part of the UNC and UNF series I know about (which are
|> in the 1/4 "  and up scale).  These threads are in the 0.5-2mm size
|> range, and initially I thought thay were small BA series.
|> 
|> I've never seen any nuts or bolts with these specifications either.
|> I can buy these taps and dies surplus, cheap, all HSS, GT, but
|> there seems th be no point if I can never match them up with
|> anything. (OK, I admit it, I bought a few anyway, and am wondering
|> if it's worth going back to clear them out!)

I have never seen "0-80 UNC" and "2-56 UNF" threads either.  However we 
commonly use "0-80 UNF" and "2-56 UNC" threads around here.  They are
common screw sizes in these parts.  If you can get screws from the States
( and it's worth the effort ) they might be usefull.  One of these days we
will get together with the rest of the world but I'm not holding my breath.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Nathan Mead				    /include(stdisclaimer);
Center for Engineering Design
University of Utah                          illigitimi non carborundum

---

From: [email-masked] (Jeff Hughes)
Date: 29 Mar 1994 21:23:52 GMT

These are American Standard numbers.  The 0-80 has a .060 inch major diameter.
The 2-56 has a .086 inch major diameter.  BTW 80 means 80 threads per inch
and 56 means 56 threads per inch.  Check your Library for a Machinery's
Handbook, it will have more info.  Those sizes are common in the USA for 
small stuff.
: Incidentally, I got a similar bargain last week. I saw a set of
: 12 BA taps, Left Hand! for £3, so I snapped them up.  List price was
: over £80.  God knows what I'll use them for.  Anyone out there got
: a LH 12BA die they don't want?

: Clive W.

: --

---

From: [email-masked] (John Wishneusky)
Date: Wed, 30 Mar 1994 15:50:43 GMT

>they are known more widely in the US. 

My Machinery's Handbook lists the following Unified threads in sizes
below .250":

   UNC:       1-64 2-56 3-48 4-40 5-40 6-32 8-32 10-24 12-24

   UNF:  0-80 1-72 2-64 3-56 4-48 5-44 6-40 8-36 10-32 12-28

John

---

From: [email-masked] (Kevin P. Martin)
Date: Thu, 31 Mar 1994 18:26:58 GMT

In article <[email-masked]> [email-masked] (Clive Washington) writes:
>
>Thanks to all who replied and mailed.  I think I have the
>picture now.  There are 12 of these threads below 1/4" and they
>are actually part of the UNC/UNF series.  They may be a
>bargain, but since I'm unlikely to get matching nuts and bolts,
>I'll probably leave them alone.
A local fastener wholesaler's catalog lists not only 0-80UNF through
12-28UNF and 1-64UNC through 12-24UNC but also carries sizes
00-90UNM (lengths 3/16" to 1/2"), 00-96UNM (3/16-3/8), 000-120 UNM
(1/8-1/4) and 0000-160UNM (1/16-1/8) in brass only. They don't say
what the actual diameter is in inches, nor do they mention what "UNM"
means (M=Microscopic?). I guess they supply these to the local
watchmaking industry :-).
	Kevin Martin, Thinkage Ltd., Kitchener, Ontario, Canada.

---

From: [email-masked] (John Wishneusky)
Date: Thu, 31 Mar 1994 17:10:20 GMT

>some day maybe we will get around to using the metric system.

Quoting from the book "Machine Tool Practices" 2nd edition:

"Machine screw sizes fall into two categories.  Fraction sizes range
from diameters of 1/4 to 3/4 in.  Below 1/4 in. diameter, screws are
identified by numbers from 0 to 12.  A number 0 machine screw has a
diameter of .060 in.  For each number above zero add .013in. to the
diameter."

John