On Sun, 28 Feb 2010 17:34:33 -0600, -MIKE- wrote:

I've had generic bar clamps, like those, over 18" bend before you feel
like you have enough pressure on them.

I've found that the HF 30" or 36" will bend a little, but the only time
I've seen the 24" or smaller bend is when I'm overclamping to make up for
a some slop that shouldn't be there.

HF used to, and may still, have two different "brands" of bar clamps.
The Pittsburgh work well, the others are junk.

As to pipe clamps, my experience has been that the heavy duty 3/4" work
fine, the others don't.

--
Intelligence is an experiment that failed - G. B. Shaw