Arfa Daily wrote in message
...
"Bill S." wrote in message
...
In article , says...
For period 1970 to 2000, whatever they are, they are not very common in
Europe. Coarser thread , diam for diam, than the usual European mm and
BA.
Common sizes are about 0.132 in outside diam. , pitch 32 TPI, would
they
be
UNC 6 ?
and 0.11 inch od and TPI about 40 , would they be 4 UNC ?
Sounds like 6-32 and 4-40.
Years ago, I worked for an American computer equipment company, and used
to
have exactly the same problem with not being able to equate the screws
fitted to the enclosures, to anything available in the UK. I won myself a
right royal bollocking from the UK director of engineering, after I had
been
speaking on the phone to one of the design enginering staff in the U.S. I
had phoned him to ask if we could get a stock of the case screws sent over
to us. "Sure" he said. "I guess I could arrange that. What size are the
ones
you want ?" "Oh" said I, "about three sixteenths APF". "APF ?" said he.
"What's APF ?" "Why, American **** Fit of course !"
Well, I *was* new to the game and only young. I didn't know much about
America and the good people who live there, and just assumed that our
humour
was the same. Didn't do anything like it again though ...
Arfa
Perhaps APF screws in aeronautics
This flight would have flown over me , not that I would have been aware that
the pilot was hanging out of the cockpit.
http://www.bbc.co.uk/dna/h2g2/A20460782
"The subsequent inquiry revealed that the windscreen had been replaced just
24 hours before the flight, and a number of errors in the procedure resulted
in the wrong size bolts being used to fit the new window. Although the
difference in size was minimal, some 200th of an inch, it was enough to
cause the windscreen to blow out when the pressure differential became too
great between the cabin and outside atmosphere."
At least when I'm hunting for the 1% or less of "American" screws in my pile
of salvaged mm and BA screws the coarse pitch makes them stand out in
comparison. I still don't know if its safe to go out and get a pack of 6-32
and 4-40 UNC machine screws for American equipment, where someone has been
there before and not replaced all.
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/