Tube grade is a higher yield and tensile. How would I know this? I sold steel for a decade. So the rated capacity holds true. The clamping system was just so so. It works but the design could use some improvements. I ended up removing clamps and used forks to fabricate a fixed 3 point set up. I installed a hydraulic top that I did purchase from vevor helping to gain all directional indexing similar to a fork lift