Slip these bad boys over your choice of 2” x 1” material and clamp away. Thin wall, thick wall. The stronger your material the stronger your clamp, the longer your tubing the longer your clamp.
With 1/8” thick wall tubing you can easily get 2500 lbs or more, the power is limited by the strength and length of the material you are using to hold the arm in place.
The spindle on these clamps are 1” diameter with 6 threads per inch and rated for over 10,000 lbs of clamping force. Extra long spindles (4.5" of spindle, 8" overall length) let you get around obstacles and really move material. A 3.5" throat depth from bar to center of pad directs the pressure where it's needed.