Shoddy Hardware (Was: Re: WW fixtures (was Re: "New" PDP-8))

From: Merle K. Peirce <at258_at_osfn.org>
Date: Fri Apr 5 18:54:07 2002

Peter, could you address how Acme threads fit into these schemes? I
should expect that they are always relatively coarse.

On Fri, 5 Apr 2002, Pete Turnbull wrote:

> On Apr 4, 23:29, Chad Fernandez wrote:
> > I've read about bolt types on Brit bikes a bit. It seems that they had
> > a variety of things they called Whitworth.
>
> Not really. See Tony's post; there are various series that use the same
> Whitworth thread form (55 degree thread angle, and rounding of crests and
> troughs) but they have different names. BSW (British Standard Whitworth)
> is the standard coarse series, analagous to ANC/UNC. BSF (British Standard
> Fine) is the corresponding fine-pitch series, analagous to ANF/UNF.
>
> There are some special-purpose threads you might have come across, such as
> BSB (British Standard Brass) which is used for finer pitch on soft metals
> (26 tpi, regardless of diameter). BSP (BS Pipe) is used for some pipe
> fittings, and is confusing because the sizes refer to the internal
> diameters of the high-pressure pipes or glands it would be used for (so
> 1/4" BSP is a little over 1/2" diameter over the threads). To add insult
> to injury, there are two types: plain, and tapered. Then there are some ME
> (Model Engineeer) threads which are very fine pitch, in two standard
> series: 32 tpi, and 40 tpi. A few of these correspond to normal
> BSW/BSF/BSB threads, but apart from that, they're relatively rare. Rarer
> still is British Standard Cycle, a fine pitch thread with a 60 degree
> thread angle, mostly 26 tpi or 32 tpi (1/8" is 40 tpi, though).
>
>
> --
> Pete Peter Turnbull
> Network Manager
> University of York
>

M. K. Peirce

Rhode Island Computer Museum, Inc.
Shady Lea, Rhode Island

"Casta est quam nemo rogavit."
              
              - Ovid
Received on Fri Apr 05 2002 - 18:54:07 BST