On Sat, 22 Sep 2007 23:27:44 -0500, Ignoramus11107
wrote:

I had a chance to thread some 1/2 NPT pipes. The threader worked,
however, the vise (Harbor Freight 4" vise) could not hold the pipe
well, so the pipe would slip. I tightened the vise rather well. This
is a vise with no special pipe holding provisions.

My question is, is the vise somenow not as good as it should be, or
was it simply a wrong tool for the job? Do vises with pipe "slots"
hold round objects better?

i
My favorite emergency pipe vise is three pipe wrenches applied from
under the pipe - the outer two to oppose the threading torque and the
middle one opposed to them. The wrenches form a tripod, holding the
pipe above the work surface, then you sit a moderately heavy load
(child, wife,sack of potatoes) on top to hold the wrench handles in
contact with the work surface.
Gerry :-)}
London, Canada