> On Jan 23, 2020, at 10:56 PM, John Ruth  wrote:
> 
> Regarding Bill’s antique tap & die set, Erik wrote:
>> I would be unsurprised if there are some uncommon items in that set. I await
the details with great interest.
> 
> Hmm, Erik! You’ve given me something to think about.  ( I have an inexplicable
fascination with obsolete threads and threading systems. )

> SNIP

> So, the 1902 founding date for American Tap and Die brings them into the
United States Standard era, which yet mean that it could contain some that
aren’t National Standard or Unified National Standard.  Also, Tap & Die sets
tend to acquire “stowaway” passengers who weren’t in the original set!
> 
> SNIP

> Yeah, verily, a Tap & Die set from the earliest days of American Tap and Die
could have some pieces that would be very useful to an antique tool collector!

I don’t know much about threads, just what I picked up on the list in passing. I
have inventoried the taps and dies in the box and almost all seem to be normal.
The odd ball I see is the 8-40 NS HSG11 taps. One reference I found said HSG is
an Acme thread, but in a number 8 that doesn’t seem right to me. The other
references I found to an 8-40 is for mounting bases in rifles, as in "8-40
screws which are extra-strength for heavier optics”. If you see anything else
exotic in there, let me know. Where the chart has duplicate entries it means
there is a regular tap and a bottoming tap. In the listing of dies the first
five are, I believe, adjustable dies. There are several manufactures represented
so the markings differ.

Bill

DIES -

5/16 18 	USS
3/8	16	USS
7/16	14	USS
1/2	13	USS
7/16	14	NC
3/16
1/4
5/16
3/8
7/16


TAPS -

1/4	20	NC
1/4	20	NC
5/16	18	USS
5/16	18	USS
3/8	16	USS
3/8	16
7/16	14	US Std
7/16	14	USS
1/2	13	US Std
9/16	18	USS
16-20
12-20	AS
12-24	NC
12-24	NC
12-24	ASME	NC
10-32
10-32	NF
10-32	NF
8-40		NS	HSG11
8-40		NS	HSG11
5-40		NC
5-40		NC
5-40		NC