I had heard so many people twitter and coo over these K-body Bessey clamps that I got four to try out.
Meh.
I guess to the inexperienced woodworker, they might be great. For making plywood boxes, I think they would be great, but that's it but maybe that's enough. I intend to get more.
I've heard they clamp up square. Well, no pics, didn't happen. Square for one side only.
this is the pressure side. Clearly it clamps up inward. That's not such a bad thing at all, but it sure as heck isn't square.
This is the fixed side. Square sure enough.
To address the original question, here's a comparison shot with the Bessey K-body at the far right.
On the left is a Jorgensen 1/2" pipe clamp. Great for plywood boxes and light glue ups
Next is the old standby, a Jorgensen 3/4" pipe clamp. Hefty enough to clamp boards together for small table top glue-ups. This is the size most everyone likes. Its very versatile and cost-efficient.
Third from the left is a Hargrave 640 . This is the newer style with the more narrow I-beam. The Jorgensen 7200 series is this type. This will clamp large board glue-ups.
Fourth is an older Hargrave 640 with a much wider I-beam. Like everyone else that has and uses them, these are my favorites for demanding glue-ups.
Lastly, on the far right is the Bessey. Its compression force is about that of the Jorgensen 3/4 pipe clamp. The "beam" is a rather thin strip of steel. Clearly it can be pressed into service for solid lumber glue-ups but it isn't ideal.
The old I-beam bar clamps are hard to find and expensive to buy. They're top of the line. Clamp users know this. I've sold a few over the years and never did my ad last more than a day. They won't be found with the retailers of shiny cheap things.