In article ,
"Bill Noble" wrote:

"Dan" wrote in message
...
Bill Noble wrote:

Dan, U.S. Air Force, retired

plausible, barely - but this thing is NOT sharp, I don't think it's
intended to cut anything -


It was the best I could come up with I hope you find out what it
is and tell us.

Over the years I have seen many specialized tools that no one outside
the trade could guess what they are for. Somewhere in my scrounge I have
a tool for shaping the points on the end of wagon spokes. It's good for
nothing else.

Dan, U.S. Air Force, retired


I've written Pratt and Whitney - we shall see if they have an answer -
meanwhile, here is my latest "brilliant" speculation - the ground part is
quite accurately ground to 1/2 inch - I just noticed that the flat part
is tapered in width, it is .194 near the pointy end, and .144 right next
to the ground round part. Further, the width of the flat part (until the
very end where it is much wider) is .565. So, if you now imagine that
this tool is slid into a 1/2 inch hole which has a keyway broached in it
that is deeper than 65 thousandths, then the thing will enter the hole
farther as the keyway gets wider - so that would make it a tool for
measuring the width of keyways.

Now, if my speculation were true, the ground 1/2 inch part would be just
under 1/2 inch so it would be a sliding fit - so I got out my best
measuring tool, an SPI digital micrometer that claims .00005 inch
accuracy and I measured it - sure enough,. 0.49950 - so it is 1/2
thousandth undersize.

This site shows some keyway width gauges
http://www.jayeshentp.com/products.htm which don't look like this at all

There is possible wear on the part that extends farther - it is .695
inches in diameter - and it goes from .18360 to .19220 - which nicely
spans 3/16 (.1875).

Ya think this could be it?


Just for giggles you might want to check your calibration/instruction
sheet for your mike. Taken out to that many places it's only accurate at
one specific temperature.

The more I look at this thing the more it looks like an eccentric wood
boring spade bit.

Then again, I have known people who would expend a lot of energy making
such a thing as a joke. When I flew RC in the 1970s I would carry a prop
wrench that wouldn't fit any nut known to man. I was always willing to
loan it at the field. I got the idea from an article in RCM magazine.

Dan, U.S. Air Force, retired

well, here is the catalog page for themicrometer -
http://www.swissprec.com/CGI/ISPDFF?PMCTLG=01&PMPAGE=19
It claims an accuracy of 16 microns, the .00005 is the display resolution -
I don't have any jobe blocks to check the calibration with, but in general
SPI is a pretty good company. I won this directly from SPI in a drawing at
a trade show - that was pretty nice....

rodger on the "looks like", but of course, it isn't..... I'm quite sure it's
part of some piece of measuring equipment - I guess if I don't find out,
I'll call it a 1/2 inch "minus" plug gauge and keep it for that purpose....

I was wondering if the pointy end of it might be some sort of dead
centre...

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg