On Thu, 22 Dec 2005 20:06:50 -0800, "Harold and Susan Vordos"
wrote:

"Andrew VK3BFA" wrote in message
roups.com...
snip----

Still dont know what an
ACME thread is. Have a small Unimat lathe

If your Unimat has a lead screw, chances are good it is an Acme thread.
The thread has an included angle of 29 degrees, and the root and crest is
flat.
Harold
Merry Christmas! (Or should that be Happy Holidays?) g
===========
As the Unimat is European there is a change it has the metric
trapezoidal thread which has a 30 degree included angle rather
than the 29 degree Acme. Anybody ever figure out why 29 and not
30 degrees?

Uncle George