Subject: Re: #0-80 and #2-56 threads (WAS does anyone know...)

From: [email-masked] (JOSEPH A. ZELINSKI)
Date: Wed, 30 Mar 1994 06:30:03 GMT

In article <[email-masked]>, [email-masked]
n (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).
         =================****************=================

    Clive:
   These threads do indeed exist in the Unified Screw Thread system. Specs
 can be readily found in Machinery's Handbook, any edition.
   #0-80 is designated as UNF: OD= .056-.060" (approx 1.5mm) 80 threads per
 inch. Correct Tap drill is .046-.051" (1.0 -1.1 mm).
   #2-56 is designated as UNC. Fine thread is #2-64 threads per inch.
 Correct OD for #2-56 is .081 to .086" with 56 threads per inch.(2.0-2.1mm)
 Correct Tap Drill is .067 to .073" (or a #50 drill).{.07-.08mm}
   Both thread sizes are still in common use in USA in lab apparatus, toys,
 eyeglasses, PC boards and the like. Screws and nuts are available in plated
 Steel, Brass, and Stainless. They are not particularly cheap, as they are
 produced in far smaller quantities than #4-40,6-32, or 8-32.
    As far as the discount prices you mentioned for taps and dies, I would
 like some more info. #0-80 HSS fluted taps retail for around $7.00 on the
 East coast...#2-56 HSS fluted taps are around $6.00. This is a Kings ransom
 when you can find #10-32 or 1/4-20 for around $2.00... (However, I recently
 found #0-80 cold forming taps {ground with flats in lieu of flutes} at a high
 priced hobby store for $1.85) Please let me know about these discount prices
 you mentioned. I use these sizes quite frequently.
                                      I Hope this clarifies things a bit!
                                                             Cheers, Joe.

---

From: [email-masked] (Don Stauffer)
Date: Wed, 30 Mar 1994 08:03:12

In article <[email-masked]> [email-masked] (JOSEPH A. ZELINSKI) writes:
>From: [email-masked] (JOSEPH A. ZELINSKI)
>Subject: Re: #0-80 and #2-56 threads  (WAS does anyone know...)
>Date: Wed, 30 Mar 1994 06:30:03 GMT

>                                      I Hope this clarifies things a bit!

Those sizes are very popular among model builders.  2-56 screws are used to 
hold the smaller model airplane engines to the firewall or engine bearers. 
The model railroaders use 0-89 and 00-90 for holding brass locomotive models 
together.  I would also be delighted to get inexpensive (not cheap, which 
implies poor quality) taps for these small sizes.  I go through them 
somewhat fast.  It is extremely easy to break a 2-56 tap!

Don in Minneapolis      [email-masked]
Don Stauffer    E-mail: [email-masked]
                Org:    Honeywell Technology Center
                        10701 Lyndale Ave South
                        Bloomington, MN 55420