On Sun, 23 Sep 2007 15:20:12 -0700, wrote:
On Sep 22, 10:27 pm, Ignoramus11107 ignoramus11...@NOSPAM.
11107.invalid 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

I'd never try to use a machinist's vise for holding pipe for
threading. If you're doing a plumbing job, rent the right tool. I
happened to inherit my granddad's pipe vise, this wraps around a post
in the cellar and is tightened down with a wedge. The pipe holding
part uses a chain to hold the pipe against a serrated V, the chain is
tightened down with a jackscrew arrangement. There are free-standing
vises using a tripod stand which are probably more useful than my
vise, they can be used where there are no cellar posts. In either
case, the pipe has to be rather firmly wedged into a number of
serrations and they've got to bite into the surface or the torque of
the die is going to spin the pipe, no matter how small. Use proper
cutting oil and lots of it, too, the black stinky stuff, it reduces
the torque needed considerably although it makes for a mess. Just lay
a lot of newspapers down under the threading area.

Stan


OK, thanks to Stan and others, I will try to find a good pipe vise.

i