"Robert Swinney" wrote in message
...
That worry kinda goes away if you grind an accurate Acme profile and feed
straight in, slowly.

Bob Swinney
"Ed Huntress" wrote in message
...

"BillMe" wrote in message
...
I need to cut an acme thread in a steel block. Roughly 5/8" X 6. I
forget what I measured! Is that done with a tap or a boring bar?
Friends have not heard of an acme tap. Thought someone might know.

Thanks,

Bill A

There are such taps. I have one, 1/2" x 10 Acme.

Boring a female Acme thread is something I've never tried. I still scratch
my head over single-point turning of *external* Acme threads. Some of the
old books tell you to cut both flanks at once, but I've never figured out
why. I made a couple of Acme threaded shafts in 1/2" x 10, and cutting on
one flank, just scraping the other, seemed to work Ok.

--
Ed Huntress

I've never seen an explanation of what you do that, Bob. Why plunge straight
in, nearly doubling the chip load, rather than feeding in on an angle and
cutting on one flank, as with conventional threads?

There must be some simple reason that I've just never come across.

--
Ed Huntress