Material for project question.

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Newbie here.http://www.weldingtipsandtricks.com/...ect-stool.htmlMy metals class students would like to build the shop stool project in the above link.We have lots of 3/4 threaded rod left over from a construction project.Would 3/4" work OK for this project?The students & I think it would work.What do you more experienced fabricators think?Thanks for looking.
Reply:As long as the length of threaded rod is kept a reasonable length, you shouldn't have any issues. The problem will be when it's extended out a ways and someone is sitting on an edge or trying to lean back on the stool. Then the 3/4" might bend. For someone who is light weight, I doubt it would make a difference, but I've seen some kids who out weigh me by a fair amount. I could see some issues with them if the 3/4" rod was fairly long and extended all the way out..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I watched both 1 & 2 parts to the video and will offer these suggestions.Be sure to fit some kind of "stop" to the bottom of the threaded rod so it can't climb out of the lower nut.And, going down in size from 1" nuts/rod (used by the video author) to 3/3" nuts/rods (you have on hand).........you might want to use 2 nuts (double nut) at the end of the rod where the stool seat plate will be attached.Using 2 nuts stacked there and joining them to the seat perimeter banding with flat stock (instead of round bar) will compensate for the loss of inherent strength because of using 3/4" versus 1" threaded material.  Other option might include simply welding some flat bar stock directly to the threaded rod below the a single 3/4" nut, notching the end at the nut so it laps over the nut as well.Welded up in that fashion there would be very little "wiggle" at that juncture.  The only thing you would lose in that configuration would be the ability to "unscrew" the seat from the threaded rod and I can't think of how that would be a bad thing.
Reply:Thank you for the responses. We will "double nut" the rod on the seat end and weld 3 struts that butt & taper out from them to seat bottom. They can design and cut the struts and seat circles on the CNC Plaz.Drill for a cotter pin on the lower end of the rod so they don't "screw it up" too far.
Reply:Sounds like a plan. I don't think you have to worry about 3/4'' rod bending. Make a mock up to test the strength of the rod. It's gonna take a lot more to bend it then you think.    Get some pics too. Thats gonna be a nice project.