On 12 Jul 2008 03:18:33 GMT, "DoN. Nichols"
wrote:

On 2008-07-11, Dave August wrote:
You are "essentially" correct about cutting left to right to get a left
handed thread, but what you forgot to say is with the spindle turning in the
"normal" clockwise direction.

He *did* say "with the machine turning in the same direction".
Here is the quoted text which you left below and which I have moved up
here to make it clear what refers to what.

If you cut from left to right with the machine turning the same
direction, do you get a left-hand thread?

Enjoy,
DoN.

there is one other gotcha.
you need to position the tool so that the body of the tool below the
cutting edge is aligned to the helix angle of the thread that you are
cutting. ...otherwise the (what do you call it??? the base, the foot
of the tool???) bit of the tool below the cutting edge will tear the
thread as it graunches past it.
this is easily achieved by tilting the tool.

the gotcha is that for threads in different directions the tilt is
reversed. the tool is set up the opposite way to a right hand thread
for left hand threads.

Stealth Pilot