Which thread gauge should I buy?

I'm going to need to identify some threading on a bicycle soon, and I
was wondering, which inch-thread system should I be looking out for.
The only gauge I've seen which specifically mentioned which system it
uses was for Whitworth threads.

Adam Rush wrote:
I'm going to need to identify some threading on a bicycle soon, and I
was wondering, which inch-thread system should I be looking out for.
The only gauge I've seen which specifically mentioned which system it
uses was for Whitworth threads.

Are you talking about thread pitch gauges, or screw pitch gauges?
If so, check out my reply in this thread:

http://groups.google.com/group/rec.b...c6e21d77755194

I give some reference sources and options for obtaining the gauges.

Cheers,
Bill

You confused me there for a minute; the link went to one of G.
Daniels's posts

I guess what I'm looking for is a thread pitch gauge. There are
several models of inch-based thread pitch gauges for sale here. The
systems they claim to use a

Whitworth
UNF
UNC

Which of these would I want to buy? My bicycle is an old (WWII)
Swedish roadster and could concievably have some English specifications
in it. Also, what on earth is UNF/UNC? Are one of those BSA or SAE?

Adam Rush writes:

I'm going to need to identify some threading on a bicycle soon, and
I was wondering, which inch-thread system should I be looking out
for. The only gauge I've seen which specifically mentioned which
system it uses was for Whitworth threads.

Here is the most common and versatile thread gauge:

http://www.generaltools.com/product....rdupc&part=251

Jobst Brandt

Adam Rush wrote:
You confused me there for a minute; the link went to one of G.
Daniels's posts

I guess what I'm looking for is a thread pitch gauge. There are
several models of inch-based thread pitch gauges for sale here. The
systems they claim to use a

Whitworth
UNF
UNC

Which of these would I want to buy? My bicycle is an old (WWII)
Swedish roadster and could concievably have some English specifications
in it. Also, what on earth is UNF/UNC? Are one of those BSA or SAE?

Sorry, I guess I should have just quoted myself. I meant that you
need to find my posting (="spin156") in that thread. In that post
I list a couple of links to thread pitch gauges.

I have a couple from Starrett Tool myself, and the one Jobst shows are
very nice. Other than metric and English, the other standard that I
know of (from working on old MGs, and Rovers) is what I was told is
"British Standard". An old car mechanic told me about British
Standard (which he explained is measured in tenths of inches) after I
complained about neither metric nor English wrenches working (i.e. many
rounded-off nuts and bolt heads). I don't think it's used anymore.
Hopefully, I got that all right. Maybe that's what you have
(???).

Adam Rush wrote:
You confused me there for a minute; the link went to one of G.
Daniels's posts

I guess what I'm looking for is a thread pitch gauge. There are
several models of inch-based thread pitch gauges for sale here. The
systems they claim to use a

Whitworth
UNF
UNC

Which of these would I want to buy? My bicycle is an old (WWII)
Swedish roadster and could concievably have some English specifications
in it. Also, what on earth is UNF/UNC? Are one of those BSA or SAE?

Hi Adam,
I found a page that explains the history of British thread types
(including all that you have listed):

http://www.enginehistory.org/british_fasteners.htm

Hope this helps ;-)

Cheers,
Bill

"Adam Rush" wrote: (clip) what on earth is UNF/UNC? Are one of those BSA
or SAE?
^^^^^^^^^^^^^^^^
I don't know about the "U," but NF is national fine, and NC is national
coarse. NF is the same as SAE.

Adam Rush writes:

Whitworth
UNF
UNC

Which of these would I want to buy? My bicycle is an old (WWII)
Swedish roadster and could conceivably have some English specifications
in it. Also, what on earth is UNF/UNC? Are one of those BSA or SAE?

Unified National Coarse/Fine back when everyone had his own thread type.
1/4-20 and 1/4-28 or 4-40 and 4-48 are examples of the coarse and fine
threads given in TPI or Threads Per Inch.

I would expect a Swedish bicycle to have metric thread but then
bicycles have always been "different" as in:

--------------------------------

The four kinds of BB threads in common use today are Italian, British,
French, and Swiss, possibly in that order of occurrence.

Diameter Pitch Right Left Cup
-------- ----- ----- -----
Italian 36mm x 24F TPI right right TPI (threads per inch)
British 1.370" x 24F TPI left right
French 35mm x 1mm right right
Swiss 35mm x 1mm left right

--------------------------------



Jobst Brandt

http://cratepro.com/

en.wikipedia.org/wiki/Linseed_oil

Adam Rush wrote:
I'm going to need to identify some threading on a bicycle soon, and I
was wondering, which inch-thread system should I be looking out for.
The only gauge I've seen which specifically mentioned which system it
uses was for Whitworth threads.

That gauge is mostly useful to Raleigh & other vintage UK
bikes and the Roadster clones of Asia.
If you can only get the WW model it is still useful on SAE
threads and covers our common 24, 26, 28 tpi. Even with the
difference of form a WW gauge is plenty accurate to tell a
24 from a 26.

Look for one with SAE and metric, which the French snootily
call "SI".
In standard DIN metric for example a 5mm bolt has a pitch of
0.8 with an 8mm wrench flat. The French version is 0.9 with
a 9mm wrench. Some "system internationale", eh?

When you say "need to identify some threading on a bicycle"
which threads? For many problems a thread gauge isn't all
that useful. For axle sets it surely helps.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971