see below, plz.
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk
To: <classiccmp(a)classiccmp.org
Sent: Wednesday, April 03, 2002 4:26 PM
Subject: Re: Shoddy Hardware (Was: Re: WW fixtures (was Re: "New" PDP-8))
> If your screws aren't 6x32's already, the easiest and probably most
practical
> thing to do is get a 6x32 roll-tap, and
"fix" the application so you can
get
the
"right" screws whenever you need.
Fine in the States, but have you tried getting 6-32 screws (or any small
UNC screws) over in the UK? They are essentially unobtainable. ISO metric
(M3) are trivial to get, so are the strange 'BA' screws (strange because
of the 47.5 degree thread angle for one thing!).
Well, no, since I haven't been in the U.K since the '60's. Since I buy
taps
by the boxful, they're cheap. The local machine tool vendor charges me the
boxful price, since I buy (or used to buy) hundreds of boxfuls per year.
Screws that sell for $0.35 at the hardware store cost $1.20 for a box of 100.
One time I threw up my hands while at the hardware store and went to a local
supply house a couple of blocks away to buy a box of washers, a box of nuts,
and a box of screws, for about $1.25 for each box that would have cost over $1
for the four of each at the hardware store. I still have some of them, BTW,
but it's a comfort knowing I don't have to be gouged each time I need 'em.
There's probably another screw, hence another tap that would work as well in
the UK, however, and I'd suggest a roll-tap in that size. They're not limited
to US in their availability, nor do they come only in "English" unit sizes.
Here in the U.S, if you go to a hardware or auto parts store and attempt to
buy a metric bolt, you can probably get it. If you try to find a matching
nut, however, it's unlikely you'll find one at a hardware or auto parts store,
since there are clearly different thread pitches available and someone decided
that it's not necessary to have similarly specified nuts and bolts that fit.
Those of you in the U.S. ought to try this if you haven't run into it yet. I
didn't realize it was possible to get nuts and bolts with matching numbers,
yet not have them fit ... only in Americal ...
A couple of my friends couldn't understand why I grabbed a couple of
boxes of random DEC screws/nuts/etc at a clearout. Well, they couldn't
understand why I did it until they came to assemble their newly-obtained
PDP11s...
DEC isn't the only vendor that used extremely odd hardware. I've had to
make
quite a bit of odd-ball stuff myself.