What is the resilience strength of rebar 3/4" tensile?

Columbia GB
by Columbia GB

Does anyone here have enough experience to know at what point 3/4" rebar will begin to bend from it's own weight when extended horizontally without support? I've looked around the internet and have only seen one project that did this. It was a stegosaurus sculpture. However, the slope coming down from the back for the neck and tail may have been a natural curve from the weight. Thoughts?

  4 answers
  • Deb K Deb K on Feb 10, 2019

    Hi, I found this, hope it helps, The minimum yield strength of standard rebar in the US is 60,000 psi. This means that the bar can have a yield strength greater then that but never less. For example, #3 rebar has a minimum yield strength of 6,600 pounds. The minimum yield strength of #4 rebar is (11,780 lbs.) 78% greater.

  • Joy30150932 Joy30150932 on Feb 10, 2019

    I have worked with 1/2 inch rebar and it is extremely sturdy. Stand alone rebar is another matter since most rebar is placed into solid ground such as concrete. Good luck with your search for the answer and your project. Sounds interesting. . If you happen to know a structural engineer, ask the question of them as they certainly would be more knowledgeable.

    • Columbia GB Columbia GB on Feb 11, 2019

      Yes, this is the issue. It's all based on supports in concrete. However, the total weight of a 10' #4 rebar is around 6.68 lbs. Which seems oddly light when you think about it. So, it may very well be possible for a 6' length to stay horizontal and not bend under it's own weight, which would be about 4 lbs. I think this needs me to stand in the box store with my trusty assistant and hold it horizontal and see what happens...

  • Dwp7470b Dwp7470b on Feb 10, 2019

    Just guessing here, as bending rebar is not common without heat, hence malleation and metallurgy done by blacksmiths, but I would have to say:


    A. It is formulaic reliant on the actual time you suspend the weights on the rebar and the heat for example:


    600lbs at 10x hours with Heat=3000lbs at 2x hours with less heat.


    The x's do equalize and force to equalize solely by finding the correct heats for each.


    B. It should bend by heat by blowtorch with 5 quantity 80lb bags of Quickrete Suspended on the rod. Whether that gives you instant gratification on the actual arc you get is unknown: Too many factors are not listed. A blacksmith could not know by the details provided.


    Please wear safety goggles, a mask and a Safety hat, while bearing in mind the general safety precautions and a matter of fact about metals: Rebar as any other metal is more likely to break than it is to bend, except under great heat. Heat is a Substitute for Pressure, pressure is a fair substitute for heat.

    • See 1 previous
    • Dwp7470b Dwp7470b on Feb 11, 2019

      It won't bow by itself! Rest assured. LOL it is like trying to bend an antique Radiator to make it fit sideways through a Door...

  • Columbia GB Columbia GB on Feb 11, 2019

    Thank you to all for your insights and comments. Very helpful! I believe this project is a go and the next step is to physically handle the bar and see what happens; extend it, give it a good shake, etc. The box store people already think I'm a bit odd, so this will confirm it.