If there is a simpler bar clamp, I have never seen one as simple as this one. I have wanted one of these clamps for a long time and now I have one. Made of 1/2″ square mild steel it has a reach of 3 1/3″ and can hold up to 12″ between jaws, with an overall length of 17″ to fit in a Medium Flat Rate box for shipping.
The prototype in the photograph is slightly shorter, clamps for sale will be slightly longer. Made by Master Blacksmith Mark Schramm, it took a couple of variations of the short piece to get it looking like the old images of this clamp.
With the addition of wooden clamp extensions [of any length] it can clamp very large panels, see illustration. Simple to use, tighten or loosen with a wooden mallet or hammer.
I am offering these for sale in The Full Chisel Store.