If my understanding is correct, the original rod clamp is designed to let screws dig into the rod itself, which does not apply well to steel rods. So I made this version that tightens its grip using a 10mm M3 screw and hex nut.
My build is not yet complete, but the 25mm wardrobe rod is already a very tight fit, and little tightening is necessary.
I apologize to the original creator of RepRack for not including their logo onto this design, that was simply out of scope.
Also inspired by https://www.printables.com/model/528265-reprack-streamlined-clamps
Print with 7 perimeters 0.3mm layer height and without support in PETG.
Update: added remix of the original 19mm (¾") version as well. I have not printed this.
The author remixed this model.
Has a single hole for a 10mm M3 screw and hex nut instead of the various holes that were supposed to dig into the rod itself. And the shape is simplified for lower material consumption.