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....

I was thinking of the thermal expansion/contraction of the work being
measured.


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....

You could always use it to clean your nails, I suppose.

Dan, U.S. Air Force, retired