On Thu, 14 Jul 2011 15:25:02 -0700, pyotr filipivich
wrote:

Ignoramus23641 on Wed, 13 Jul
2011 17:04:00 -0500 typed in rec.crafts.metalworking the following:
Would it be safe to work under a jacked vehicle, if I use a mechanical
jack like this:

https://picasaweb.google.com/lh/phot...eat=directlink


Safer than what?

The problem with jacks is that they are meant to move, under a
load, and lower vehicles. Mechanical jacks are _less_ likely to do
that than a hydraulic jack, if only because there is less possibility
of a seal failing.
First jack I ever bought consisted of a 4 inch square base plate with
a dimple in the centre, a 30inch length of 3/4" acme threaded rod, a
hook shaped nut to engage the bumper and an "L" shaped rod to fit the
hole in the upper end of thet threaded rod. Greatest gadget for
getting the car to move sidewise from a stuck position in soft ground,
just pick up the end of the car and push side.ways. Of course you
needed a couple people to steady the car until it was time to move it
sideways
Gerry :-)}
London, Canada