On Thu, 4 Nov 2010 12:41:46 -0700 (PDT), Christopher Tidy
wrote:

On Nov 4, 7:27*pm, wws wrote:

Flat lapping is legitimate.
Think microns, such as optical flats.
Maybe Chinese?

I did wonder if the word was flat. Here's the pictu
http://books.google.co.uk/books?id=-...rat+lapping%22

404 error.


According to Google, it's "rat". But flat or part sounds more
sensible.

SWAG:
Perhaps scraping/lapping with a rat-tail file which was ground into a
scraper? shrug

--
Experience is a good teacher, but she send in terrific bills.
-- Minna Thomas Antrim