works great to hold pipe, c channel and I-beams. I have used them to level steel for cutting with chop saw, plazma cutter and weld.
I would give it five stars but the washer that you use to raise and lower the sleeve seems a bit uneven. Otherwise it's great, I originally bought the 42" and wished I would have bought 2 of the 52" in the first place. I would buy it again.