My question is: Researching two sizes of square steel tubing to use for a project. material 2 inch square tubing with 0.25 thick wall and 3 inch square tubing with 0.25 thick wall. The square steel tubing will be welded on to a frame at an angle so the corners point up and down , or another way of saying it, the corners will be where the ends of the letter "t" or an addition sign "+" are. For each tube size what force would be needed to bend the tube? Want to build a gravel grizzly to screen out rock from sand in gravel pit. The wheel loader bucket of gravel; would be slowing dumped onto the square steel tubing. Maximum weight that would be dumped is 7500 pounds. A full loader bucket of gravel. Surface area that gravel would be dumped onto is 8 feet wide and 4 feet long with a steel support 1 foot in from edge of the 4 feet long area. Length of the incline (slope) of steel tubing top to bottom 8 feet long. Slope angle is 40 degrees. From top of the steel tubing where the slope begins go down slope 2.5 feet, this will be the location of the steel brace under each steel tube and the remaining 5.5 feet of length no support under it, until the end of the slope where it will be welded to the frame. The gravel will have mostly screened out through the steel bars at the 4 to 5 foot mark from the top. Only over size rocks that did not go through the bar spacing of 1 inch, would travel the rest of the way over the bars to the edge of the grizzly and off the deck Largest rock/boulder I think going on the steel bars would be 18 inch round rock weighting 1,700 pounds. Attached are two photos of what a grizzly screen for gravels. Similar to what I want to build. Photos worth a 1,000 words. 18 steel bars over a 10 foot width, the bucket is 8 feet wide. Steel bar then 1 inch opening, then another steel bar, another 1 inch opening; etc. over the 10 foot wide area. So lot of steel bar surface in contact with bucket load of gravel. But I need to know if the 2 inch square steel would bend under the weight of the gravel or large rock, given the area that is not supported be bracing under the steel bars. Each steel bar would be braced a the 2.5 foot mark from the top to the slope. So it's the distance from the 2.5 foot mark to the 4 to 5 foot mark where most of the gravel would have gone though the bar openings that I am wondering if the bars would bend with in this 3 foot area. Bucket reaches over the top of the grizzly and dumps the gravel onto the deck of steel bars at about 1 to 2 feet in from top, with most gravel at the 2.5 feet to 4 feet from top area. The four foot impact area is 1 foot then the steel brace then the 3 feet, by then most gravel through the bars only rocks on top to slide off the bars and over end of sloping deck. Any input would be greatly appreciated. These small gravel grizzly plants cost around $10,000 with freight and taxes, That's not cost effective (it can not pay for itself with my small operation) so I have to make one myself.