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


The jaws are supposed to dig into the pipe. If they are not sharp, or
heat treated well enough, they will slip.

I just got done hanging 1100' of black pipe air lines. I have both an
Oster pipe threader and the Rigid tripod vise for fitting work and so
forth, and had to regrind the jaws twice to keep them from slipping

There are two main types of pipe vise. The chain vise, and the clamp
vise. I actually prefer the clamp vise, given dull jaws in both.
I will be rigging up the KO Lee tool cutter grinder to recut all the
jaws now that the Project is winding down, in preperation for the next
project.

Ive also learned to not skimp on pipe wrenches. While the $5 Harbor
Freight wrenches are inexpensive, they tend to have soft jaws and
after some use in a commercial application..dull quickly and stop
holding. For home use, they are fine.
So I scrounged up some beat up old Rigid pipe wrenches, and they, even
beat up, held better than some new HF wrenchs

Gunner