On 2009-03-18, Bill Noble wrote:

"Ignoramus4181" wrote in message
...
On 2009-03-17, Wild_Bill wrote:
Making of a Big Tap at Widell

http://www.widell.com/bigtap01.html


Nice pictures. Interestingly, their grinder was imported by Shars,
which we just discussed here.


also interesting - I always figured you would first turn threads, then cut
flutes, then harden, but clearly that is not the way it's done - cut flutes
and heat treat, then cut threads

Somewhat unrelated, but my guess is that it is for a pipe inside a
pipe type of situation, maybe a huge heat exchanger.

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