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263921 Claudio DeLorenzi <claudio@d...> 2017‑11‑13 Re: Hot mic
Re Micrometers (I love precision tools!)
One of my small ones came with a small ball anvil, I guess for precision
indicating on round stock?  I can’t recall off hand if any of the small
mics came with any standard, but these were always estate sales or flea
market buys, and people often take out stuff from the cases if they don’t
know the purpose of the part.  You sometimes see the little wrenches and
standards (even gauge blocks) on sales tables, long separated from their
micrometer or tool sets and sellers who have no idea what they are.
   Don’t some of the vernier scale mikes measure in tenths so the
resolution is indeed 0.0001 (0.001”/10)?  One complete turn on a 40TPI
thread is 1/40=25 thou .   The main division on the mic thimble is in thou,
and the vernier divides each thou by 10, ie does the last tenth on the
sleeve (or whatever that part is called, with the longitudinal lines- and
yes I realize that we are interpolating a bit on these, and all we are
really doing is narrowing the error bars).

   Even without the vernier, you can guess whether you are half way between
the marks (ie plus or minus 5/10ths, ie 0.0005).
  Either that, or I have been doing it wrong, haha.  Maybe a real machinist
can chime in here?  I don’t use these every day, so I don’t have a high
confidence level in my info.
Cheers from Waterloo
Claudio

Recent Bios FAQ